462 lines
58 KiB
XML
462 lines
58 KiB
XML
<document ID-DOI="http://doi.org/10.5281/zenodo.4658230" ID-GBIF-Dataset="71bdd341-af13-4447-ba22-9b2bb8de2f80" ID-GBIF-Taxon="180784329" ID-ISSN="0067-1975" ID-Zenodo-Dep="4658230" checkinTime="1617215540781" checkinUser="felipe" docAuthor="Edgecombe, Gregory D." docDate="1998" docId="03FE7A7C2D49FFBBFEAFFA80FA467D73" docLanguage="en" docName="RecAustMus.50.3.293-313.pdf.imf" docOrigin="Records of the Australian Museum 50 (3)" docSource="https://journals.australian.museum/edgecombe-1998-rec-aust-mus-503-293313/" docStyle="DocumentStyle:CF64E561BE6B94FA5F31B9132C6D4316.1:RecAustMus.1998.journal_article" docStyleId="CF64E561BE6B94FA5F31B9132C6D4316" docStyleName="RecAustMus.1998.journal_article" docStyleVersion="1" docTitle="Maldybulakia Tesakov & Alekseev 1998" docType="treatment" docVersion="8" lastPageId="5" lastPageNumber="298" masterDocId="FFC702042D4AFFBEFFFFFFE8FFA1714A" masterDocTitle="Early myriapodous arthropods from Australia: Maldybulakia from the Devonian of New South Wales" masterLastPageNumber="313" masterPageNumber="293" pageId="3" pageNumber="296" updateTime="1643595242968" updateUser="ExternalLinkService">
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<mods:mods xmlns:mods="http://www.loc.gov/mods/v3">
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<mods:titleInfo>
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<mods:title>Early myriapodous arthropods from Australia: Maldybulakia from the Devonian of New South Wales</mods:title>
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</mods:titleInfo>
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<mods:name type="personal">
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<mods:role>
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<mods:roleTerm>Author</mods:roleTerm>
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</mods:role>
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<mods:namePart>Edgecombe, Gregory D.</mods:namePart>
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</mods:name>
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<mods:typeOfResource>text</mods:typeOfResource>
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<mods:titleInfo>
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<mods:title>Records of the Australian Museum</mods:title>
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</mods:titleInfo>
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<mods:part>
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<mods:date>1998</mods:date>
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<mods:detail type="pubDate">
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<mods:number>1998-11-25</mods:number>
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</mods:detail>
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<mods:detail type="volume">
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<mods:number>50</mods:number>
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</mods:detail>
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<mods:detail type="issue">
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<mods:number>3</mods:number>
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</mods:detail>
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<mods:extent unit="page">
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<mods:start>293</mods:start>
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<mods:end>313</mods:end>
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</mods:extent>
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</mods:part>
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</mods:relatedItem>
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<mods:location>
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<mods:url>https://journals.australian.museum/edgecombe-1998-rec-aust-mus-503-293313/</mods:url>
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</mods:location>
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<mods:classification>journal article</mods:classification>
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<mods:identifier type="DOI">10.3853/j.0067-1975.50.1998.1288</mods:identifier>
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<mods:identifier type="GBIF-Dataset">71bdd341-af13-4447-ba22-9b2bb8de2f80</mods:identifier>
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<mods:identifier type="ISSN">0067-1975</mods:identifier>
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<mods:identifier type="Zenodo-Dep">4653146</mods:identifier>
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</mods:mods>
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<treatment ID-DOI="http://doi.org/10.5281/zenodo.4658230" ID-GBIF-Taxon="180784329" ID-Zenodo-Dep="4658230" LSID="urn:lsid:plazi:treatment:03FE7A7C2D49FFBBFEAFFA80FA467D73" httpUri="http://treatment.plazi.org/id/03FE7A7C2D49FFBBFEAFFA80FA467D73" lastPageId="5" lastPageNumber="298" pageId="3" pageNumber="296">
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<subSubSection box="[336,1078,1384,1423]" pageId="3" pageNumber="296" type="nomenclature">
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<paragraph blockId="3.[336,1078,1384,1423]" box="[336,1078,1384,1423]" pageId="3" pageNumber="296">
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<heading box="[336,1078,1384,1423]" centered="true" fontSize="10" level="2" pageId="3" pageNumber="296" reason="2">
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<taxonomicName authority="Tesakov & Alekseev, 1998" authorityName="Tesakov & Alekseev" authorityYear="1998" box="[336,1078,1384,1423]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="3" pageNumber="296" phylum="Arthropoda" rank="genus">
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<emphasis box="[336,583,1384,1423]" italics="true" pageId="3" pageNumber="296">Maldybulakia</emphasis>
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<bibRefCitation author="Tesakov, A. S. & A. S. Alekseev" box="[602,1078,1384,1423]" pageId="3" pageNumber="296" pagination="49" refId="ref13889" refString="Tesakov, A. S., & A. S. Alekseev, 1998. Maldybulakia-new name for Lophodesmus Tesakov and Alekseev, 1992 (Arthropoda). Palaeontological Journal 32: 49." type="journal article" year="1998">Tesakov & Alekseev, 1998</bibRefCitation>
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</taxonomicName>
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</heading>
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</paragraph>
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</subSubSection>
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<subSubSection pageId="3" pageNumber="296" type="reference_group">
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<paragraph blockId="3.[221,1200,1489,1566]" box="[221,1200,1489,1524]" pageId="3" pageNumber="296">
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<bibRefCitation author="Tesakov, A. S. & A. S. Alekseev" box="[221,296,1489,1524]" pageId="3" pageNumber="296" pagination="18 - 23" refId="ref13855" refString="Tesakov, A. S., & A. S. Alekseev, 1992. Myriapod-like arthropods from the Lower Devonian of central Kazakhstan. Paleontological Journal 26: 18 - 23." type="journal article" year="1992">
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<emphasis box="[221,296,1489,1524]" italics="true" pageId="3" pageNumber="296">1992</emphasis>
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</bibRefCitation>
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<taxonomicName authority="Tesakov & Alekseev" authorityName="Tesakov & Alekseev" authorityYear="1992" box="[336,979,1489,1524]" class="Diplopoda" family="Pyrgodesmidae" genus="Lophodesmus" kingdom="Animalia" order="Polydesmida" pageId="3" pageNumber="296" phylum="Arthropoda" rank="genus">
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<emphasis box="[336,573,1489,1524]" italics="true" pageId="3" pageNumber="296">Lophodesmus</emphasis>
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Tesakov & Alekseev
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</taxonomicName>
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, 1992 (non
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</paragraph>
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<paragraph blockId="3.[221,1200,1489,1566]" box="[336,810,1531,1566]" pageId="3" pageNumber="296">
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<taxonomicName authority="Pocock, 1894" authorityName="Pocock" authorityYear="1894" box="[336,794,1531,1566]" class="Diplopoda" family="Pyrgodesmidae" genus="Lophodesmus" kingdom="Animalia" order="Polydesmida" pageId="3" pageNumber="296" phylum="Arthropoda" rank="genus">
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<emphasis box="[336,552,1531,1566]" italics="true" pageId="3" pageNumber="296">Lophodesmus</emphasis>
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<bibRefCitation author="Pocock, R. I." box="[570,794,1531,1566]" pageId="3" pageNumber="296" pagination="307 - 404" refId="ref13378" refString="Pocock, R. I., 1894. Chilopoda, Symphyla, and Diplopoda from the Malay Archipelago. In Zoologische Ergebnisse einer Reise in Niederliindisch Ost-Indien volume 3, ed. M. Weber, pp. 307 - 404." type="book chapter" year="1894">Pocock, 1894</bibRefCitation>
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</taxonomicName>
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).
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</paragraph>
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</subSubSection>
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<subSubSection pageId="3" pageNumber="296" type="type_taxon">
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<paragraph blockId="3.[217,1198,1632,1717]" pageId="3" pageNumber="296">
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<typeStatus box="[217,304,1632,1671]" pageId="3" pageNumber="296">Type</typeStatus>
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species.
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<taxonomicName authority="Tesakov & Alekseev, 1992" authorityName="Tesakov & Alekseev" authorityYear="1992" class="Diplopoda" family="Pyrgodesmidae" genus="Lophodesmus" kingdom="Animalia" order="Polydesmida" pageId="3" pageNumber="296" phylum="Arthropoda" rank="species" species="mirabilis">
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<emphasis box="[456,843,1632,1671]" italics="true" pageId="3" pageNumber="296">Lophodesmus mirabilis</emphasis>
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<bibRefCitation author="Tesakov, A. S. & A. S. Alekseev" pageId="3" pageNumber="296" pagination="18 - 23" refId="ref13855" refString="Tesakov, A. S., & A. S. Alekseev, 1992. Myriapod-like arthropods from the Lower Devonian of central Kazakhstan. Paleontological Journal 26: 18 - 23." type="journal article" year="1992">Tesakov & Alekseev, 1992</bibRefCitation>
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</taxonomicName>
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.
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</paragraph>
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</subSubSection>
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<subSubSection pageId="3" pageNumber="296" type="diagnosis">
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<paragraph blockId="3.[213,1199,1783,2373]" pageId="3" pageNumber="296">Diagnosis. Large myriapodous arthropod with strongly mineralised pleurotergum, unmineralised sternum; cuticular surface with dense, polygonal sculpture; cuticle densely penetrated by large pore canals; trunk composed of two tagmata of presumed diplotergites; anterior tagma of one or possibly two subtrapezoidal tergite(s) having rounded corners; posterior tagma composed of at least four pleurotergites with pair of triangular lateral lobes on metazonites and short to long paratergal spines; pleurites coalesced with metazonites only; posterior-most (fifth) bilobate tergite with median spine-like process; spiracle in pleural furrow on third pleurotergite of posterior tagma; presumed telson composed of two small sclerites.</paragraph>
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</subSubSection>
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<subSubSection lastPageId="5" lastPageNumber="298" pageId="3" pageNumber="296" type="discussion">
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<paragraph blockId="3.[210,1201,2439,3167]" pageId="3" pageNumber="296">
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Discussion.
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<taxonomicName authority="Tesakov & Alekseev, 1998" authorityName="Tesakov & Alekseev" authorityYear="1998" box="[423,1115,2439,2478]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="3" pageNumber="296" phylum="Arthropoda" rank="genus">
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<emphasis box="[423,654,2439,2478]" italics="true" pageId="3" pageNumber="296">Maldybulakia</emphasis>
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<bibRefCitation author="Tesakov, A. S. & A. S. Alekseev" box="[666,1115,2439,2478]" pageId="3" pageNumber="296" pagination="49" refId="ref13889" refString="Tesakov, A. S., & A. S. Alekseev, 1998. Maldybulakia-new name for Lophodesmus Tesakov and Alekseev, 1992 (Arthropoda). Palaeontological Journal 32: 49." type="journal article" year="1998">Tesakov & Alekseev, 1998</bibRefCitation>
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</taxonomicName>
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, was recently proposed as a replacement name for
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<taxonomicName authority="Tesakov & Alekseev, 1992" authorityName="Tesakov & Alekseev" authorityYear="1992" class="Diplopoda" family="Pyrgodesmidae" genus="Lophodesmus" kingdom="Animalia" order="Polydesmida" pageId="3" pageNumber="296" phylum="Arthropoda" rank="genus">
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<emphasis box="[967,1198,2485,2524]" italics="true" pageId="3" pageNumber="296">Lophodesmus</emphasis>
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<bibRefCitation author="Tesakov, A. S. & A. S. Alekseev" box="[213,665,2531,2571]" pageId="3" pageNumber="296" pagination="18 - 23" refId="ref13855" refString="Tesakov, A. S., & A. S. Alekseev, 1992. Myriapod-like arthropods from the Lower Devonian of central Kazakhstan. Paleontological Journal 26: 18 - 23." type="journal article" year="1992">Tesakov & Alekseev, 1992</bibRefCitation>
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</taxonomicName>
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, a name occupied by the extant polydesmid millipede
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<taxonomicName authority="Pocock, 1894" authorityName="Pocock" authorityYear="1894" box="[611,1108,2578,2617]" class="Diplopoda" family="Pyrgodesmidae" genus="Lophodesmus" kingdom="Animalia" order="Polydesmida" pageId="3" pageNumber="296" phylum="Arthropoda" rank="genus">
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<emphasis box="[611,846,2578,2617]" italics="true" pageId="3" pageNumber="296">Lophodesmus</emphasis>
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<bibRefCitation author="Pocock, R. I." box="[864,1108,2578,2617]" pageId="3" pageNumber="296" pagination="307 - 404" refId="ref13378" refString="Pocock, R. I., 1894. Chilopoda, Symphyla, and Diplopoda from the Malay Archipelago. In Zoologische Ergebnisse einer Reise in Niederliindisch Ost-Indien volume 3, ed. M. Weber, pp. 307 - 404." type="book chapter" year="1894">Pocock, 1894</bibRefCitation>
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</taxonomicName>
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. The generic diagnosis employed by
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<bibRefCitation author="Tesakov, A. S. & A. S. Alekseev" box="[737,1197,2623,2662]" pageId="3" pageNumber="296" pagination="18 - 23" refId="ref13855" refString="Tesakov, A. S., & A. S. Alekseev, 1992. Myriapod-like arthropods from the Lower Devonian of central Kazakhstan. Paleontological Journal 26: 18 - 23." type="journal article" year="1992">Tesakov & Alekseev (1992)</bibRefCitation>
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is modified to account for newly discovered diversity in the Devonian of
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<collectingCountry box="[505,661,2715,2754]" name="Australia" pageId="3" pageNumber="296">Australia</collectingCountry>
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.
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</paragraph>
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<paragraph blockId="3.[210,1201,2439,3167]" lastBlockId="3.[1269,2257,417,3168]" pageId="3" pageNumber="296">
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A major morphological contribution of new Australian species
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<emphasis box="[342,622,2807,2846]" italics="true" pageId="3" pageNumber="296">ofMaldybulakia</emphasis>
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is to elucidate the nature of trunk tagmosis in this arthropod.
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<bibRefCitation author="Tesakov, A. S. & A. S. Alekseev" box="[704,1196,2853,2892]" pageId="3" pageNumber="296" pagination="18 - 23" refId="ref13855" refString="Tesakov, A. S., & A. S. Alekseev, 1992. Myriapod-like arthropods from the Lower Devonian of central Kazakhstan. Paleontological Journal 26: 18 - 23." type="journal article" year="1992">Tesakov & Alekseev (1992)</bibRefCitation>
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identified two tergite
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<typeStatus box="[682,781,2899,2938]" pageId="3" pageNumber="296">types</typeStatus>
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in beds containing
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<emphasis box="[210,642,2945,2984]" italics="true" pageId="3" pageNumber="296">
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<taxonomicName baseAuthorityName="Tesakov & Alekseev" baseAuthorityYear="1992" box="[210,637,2945,2984]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="3" pageNumber="296" phylum="Arthropoda" rank="species" species="mirabilis">Maldybulakia mirabilis</taxonomicName>
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.
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</emphasis>
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The
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<typeStatus box="[747,820,2945,2984]" pageId="3" pageNumber="296">type</typeStatus>
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material consists of tergites regarded by them as diplosegments, with the lateral part of the "metazonite" swollen into a rounded lobe, and a spinose projection from the lateral edge of the paratergum. This tergite
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<typeStatus box="[636,706,3129,3167]" pageId="3" pageNumber="296">type</typeStatus>
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will hereafter be referred to as a bilobate pleurotergite or B-pleurotergite (specimens of
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<taxonomicName authority="Edgecombe, 1998" authorityName="Edgecombe" authorityYear="1998" box="[1324,1541,463,501]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="3" pageNumber="296" phylum="Arthropoda" rank="species" species="malcolmi" status="n.sp.">
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<emphasis box="[1324,1541,463,501]" italics="true" pageId="3" pageNumber="296">M. malcolmi</emphasis>
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</taxonomicName>
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<taxonomicNameLabel box="[1559,1635,463,501]" pageId="3" pageNumber="296" rank="species">n.sp.</taxonomicNameLabel>
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are interpreted as having pleurites fused to the tergum, thus the use of "pleurotergites").
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</paragraph>
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<paragraph blockId="3.[1269,2257,417,3168]" pageId="3" pageNumber="296">
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Associated with the B-pleurotergites is a second, less common tergite
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<typeStatus box="[1563,1634,601,640]" pageId="3" pageNumber="296">type</typeStatus>
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of "simple structure and roundedrectangular outline" (
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<bibRefCitation author="Tesakov, A. S. & A. S. Alekseev" box="[1663,2234,647,686]" pageId="3" pageNumber="296" pagination="18 - 23" refId="ref13855" refString="Tesakov, A. S., & A. S. Alekseev, 1992. Myriapod-like arthropods from the Lower Devonian of central Kazakhstan. Paleontological Journal 26: 18 - 23." type="journal article" year="1992">Tesakov & Alekseev, 1992: 19</bibRefCitation>
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). Noting that the rectangular (or, more accurately, trapezoidal) tergites bore a similar sculpture to the bilobate diplotergites/B-pleurotergites,
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<bibRefCitation author="Tesakov, A. S. & A. S. Alekseev" pageId="3" pageNumber="296" pagination="18 - 23" refId="ref13855" refString="Tesakov, A. S., & A. S. Alekseev, 1992. Myriapod-like arthropods from the Lower Devonian of central Kazakhstan. Paleontological Journal 26: 18 - 23." type="journal article" year="1992">Tesakov & Alekseev (1992)</bibRefCitation>
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acknowledged the likelihood that they could belong to the same animal. However, they interpreted the trapezoidal tergites as neck segments, but (assuming one neck segment per animal, as for the dignathan collum) found them to be anomalously common relative to the typical B-pleurotergites.
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</paragraph>
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<paragraph blockId="3.[1269,2257,417,3168]" pageId="3" pageNumber="296">
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Conclusive evidence that the trapezoidal tergites (here abbreviated T-tergites) are actually part of
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<taxonomicName authorityName="Tesakov & Alekseev" authorityYear="1998" box="[2020,2253,1154,1192]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="3" pageNumber="296" phylum="Arthropoda" rank="genus">
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<emphasis box="[2020,2253,1154,1192]" italics="true" pageId="3" pageNumber="296">Maldybulakia</emphasis>
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</taxonomicName>
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is provided by the Australian species, in particular by several articulated specimens of
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<emphasis box="[1902,2147,1246,1284]" italics="true" pageId="3" pageNumber="296">
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<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[1902,2142,1246,1284]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="3" pageNumber="296" phylum="Arthropoda" rank="species" species="malcolmi">M. malcolmi</taxonomicName>
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.
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</emphasis>
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Four articulated specimens of
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<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[1722,1947,1292,1330]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="3" pageNumber="296" phylum="Arthropoda" rank="species" species="malcolmi">
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<emphasis box="[1722,1947,1292,1330]" italics="true" pageId="3" pageNumber="296">M. malcolmi</emphasis>
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</taxonomicName>
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have a single Ttergite attached or slightly displaced from the front of a series of B-pleurotergites. In the
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<typeStatus box="[1853,2003,1384,1422]" pageId="3" pageNumber="296">holotype</typeStatus>
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, a T-tergite of nearly the same size as the articulated one (width 14.4 versus
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<quantity box="[1401,1552,1475,1514]" metricMagnitude="-2" metricUnit="m" metricValue="1.48" pageId="3" pageNumber="296" unit="mm" value="14.8">14.8 mm</quantity>
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, respectively) is displaced
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<quantity box="[2038,2157,1475,1514]" metricMagnitude="-2" metricUnit="m" metricValue="1.4" pageId="3" pageNumber="296" unit="mm" value="14.0">14 mm</quantity>
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from the front of the specimen. Considering the scarcity of specimens this small it is not unlikely that the displaced tergite belongs to the same individual, which would thus possess two T-tergites. The failure to find T-tergites in articulation with each other in any specimens may derive from a mainly membranous attachment and simple overlap (in contrast to the strong articulations developed between B-pleurotergites).
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<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[1578,1937,1843,1882]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="3" pageNumber="296" phylum="Arthropoda" rank="species" species="angusi">
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<emphasis box="[1578,1937,1843,1882]" italics="true" pageId="3" pageNumber="296">Maldybulakia angusi</emphasis>
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</taxonomicName>
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reveals a range of morphology within this tergite type, suggestive of two or more T-tergites represented within a tagma of generally similar tergite form. The T-tergites vary in the presence or absence of a posteromedian spine, the prominence of tubercles, the degree of sinuosity of the transverse furrow, and the presence or absence of lateral swellings.
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<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[1269,1697,2165,2204]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="3" pageNumber="296" phylum="Arthropoda" rank="species" species="malcolmi">
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<emphasis box="[1269,1697,2165,2204]" italics="true" pageId="3" pageNumber="296">Maldybulakia malcolmi</emphasis>
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</taxonomicName>
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and
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<taxonomicName baseAuthorityName="Tesakov & Alekseev" baseAuthorityYear="1992" box="[1798,2023,2165,2204]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="3" pageNumber="296" phylum="Arthropoda" rank="species" species="mirabilis">
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<emphasis box="[1798,2023,2165,2204]" italics="true" pageId="3" pageNumber="296">M. mirabilis</emphasis>
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</taxonomicName>
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display less morphological differentiation between the tergites of this tagma than is the case for
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<emphasis box="[1739,1922,2257,2295]" italics="true" pageId="3" pageNumber="296">
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<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[1739,1917,2257,2295]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="3" pageNumber="296" phylum="Arthropoda" rank="species" species="angusi">M. angusi</taxonomicName>
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.
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</emphasis>
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This is consistent with evidence from the tagma composed of Bpleurotergites, wherein
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[1686,1862,2349,2387]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="3" pageNumber="296" phylum="Arthropoda" rank="species" species="angusi">
|
|
<emphasis box="[1686,1862,2349,2387]" italics="true" pageId="3" pageNumber="296">M. angusi</emphasis>
|
|
</taxonomicName>
|
|
shows a much greater degree of variation than seen in the other two species.
|
|
</paragraph>
|
|
<paragraph blockId="3.[1269,2257,417,3168]" lastBlockId="4.[217,1210,414,3166]" lastPageId="4" lastPageNumber="297" pageId="3" pageNumber="296">
|
|
The frequency of occurrence of the trapezoidal tergites-27 percent of the sample (N=44)-was cited by
|
|
<bibRefCitation author="Tesakov, A. S. & A. S. Alekseev" box="[1271,1796,2532,2571]" pageId="3" pageNumber="296" pagination="18 - 23" refId="ref13855" refString="Tesakov, A. S., & A. S. Alekseev, 1992. Myriapod-like arthropods from the Lower Devonian of central Kazakhstan. Paleontological Journal 26: 18 - 23." type="journal article" year="1992">Tesakov & Alekseev (1992)</bibRefCitation>
|
|
as a difficulty for their interpretation of the T-tergites as neck segments. Variable frequencies of occurrence of the T- and B-tergites are observed for the two Australian species of
|
|
<taxonomicName authorityName="Tesakov & Alekseev" authorityYear="1998" box="[2023,2254,2670,2709]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="3" pageNumber="296" phylum="Arthropoda" rank="genus">
|
|
<emphasis box="[2023,2254,2670,2709]" italics="true" pageId="3" pageNumber="296">Maldybulakia</emphasis>
|
|
</taxonomicName>
|
|
(
|
|
<figureCitation box="[1284,1390,2716,2755]" captionStart="Figure 2" captionStartId="5.[375,483,2155,2194]" captionTargetBox="[413,2080,498,2064]" captionTargetPageId="5" captionText="Figure 2. Relative abundances of different sclerite types at localities yielding Maldybulakia. (a) expected frequency of occurrence for M. malcolmi n.sp. based on one T-tergite, one ring tergite, four B-pleurotergites, and one caudal pleurotergite in articulated specimens. (b) sampled frequency of occurrence based on 223 disarticulated sclerites of M. malcolmi. (c) sampled frequency of occurrence based on 301 disarticulated sclerites of M. angusi n.sp. (d) sampled frequency of occurrence based on 44 disarticulated sclerites of M. mirabilis (Tesakov & Alekseev, 1992)." figureDoi="http://doi.org/10.5281/zenodo.4658419" httpUri="https://zenodo.org/record/4658419/files/figure.png" pageId="3" pageNumber="296">Fig. 2</figureCitation>
|
|
). The relative extent of the two tagmata might be estimated by the relative abundance of T- and B-tergites, although it appears that taphonomic factors have biased the samples. Three articulated specimens of
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[2040,2254,2854,2893]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="3" pageNumber="296" phylum="Arthropoda" rank="species" species="malcolmi">
|
|
<emphasis box="[2040,2254,2854,2893]" italics="true" pageId="3" pageNumber="296">M. malcolmi</emphasis>
|
|
</taxonomicName>
|
|
(
|
|
<collectionCode box="[1283,1351,2900,2939]" country="Australia" name="Australian Museum" pageId="3" pageNumber="296" type="Museum">AM</collectionCode>
|
|
F.102533, 102535, 102357) have a single T-tergite followed by four B-pleurotergites, then a caudal tergite as figured for
|
|
<taxonomicName baseAuthorityName="Tesakov & Alekseev" baseAuthorityYear="1992" box="[1470,1683,2992,3030]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="3" pageNumber="311" phylum="Arthropoda" rank="species" species="mirabilis">
|
|
M.
|
|
<emphasis box="[1532,1683,2992,3030]" italics="true" pageId="3" pageNumber="296">mirabilis</emphasis>
|
|
</taxonomicName>
|
|
by
|
|
<bibRefCitation author="Tesakov, A. S. & A. S. Alekseev" box="[1760,2247,2992,3030]" pageId="3" pageNumber="296" pagination="18 - 23" refId="ref13855" refString="Tesakov, A. S., & A. S. Alekseev, 1992. Myriapod-like arthropods from the Lower Devonian of central Kazakhstan. Paleontological Journal 26: 18 - 23." type="journal article" year="1992">Tesakov & Alekseev (1992)</bibRefCitation>
|
|
. The caudal tergite is quite clearly a modified Bpleurotergite, showing the rounded lateral lobes and depressed, anterior overlapped surface (prozonite) typical of those pleurotergites. This serial homology is also obvious in
|
|
<emphasis box="[439,683,460,500]" italics="true" pageId="4" pageNumber="297">
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[439,677,460,500]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="malcolmi">M. malcolmi</taxonomicName>
|
|
,
|
|
</emphasis>
|
|
in which the caudal tergite possesses small posterolateral projections as in the Bpleurotergites.
|
|
</paragraph>
|
|
<paragraph blockId="4.[217,1210,414,3166]" pageId="4" pageNumber="297">
|
|
For
|
|
<emphasis box="[343,709,598,638]" italics="true" pageId="4" pageNumber="297">
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[343,703,598,638]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="angusi">Maldybulakia angusi</taxonomicName>
|
|
,
|
|
</emphasis>
|
|
a survey of 301 sclerites that could be confidently identified.as either a T-tergite, ring tergite, B-pleurotergite or caudal tergite shows that Ttergites comprise 32 percent of the sample and Bpleurotergites 66 percent (
|
|
<figureCitation box="[662,780,782,822]" captionStart="Figure 2" captionStartId="5.[375,483,2155,2194]" captionTargetBox="[413,2080,498,2064]" captionTargetPageId="5" captionText="Figure 2. Relative abundances of different sclerite types at localities yielding Maldybulakia. (a) expected frequency of occurrence for M. malcolmi n.sp. based on one T-tergite, one ring tergite, four B-pleurotergites, and one caudal pleurotergite in articulated specimens. (b) sampled frequency of occurrence based on 223 disarticulated sclerites of M. malcolmi. (c) sampled frequency of occurrence based on 301 disarticulated sclerites of M. angusi n.sp. (d) sampled frequency of occurrence based on 44 disarticulated sclerites of M. mirabilis (Tesakov & Alekseev, 1992)." figureDoi="http://doi.org/10.5281/zenodo.4658419" httpUri="https://zenodo.org/record/4658419/files/figure.png" pageId="4" pageNumber="297">Fig. 2c</figureCitation>
|
|
). It might thus be inferred that the anterior tagmata composed of T-tergites is half the length of the tagmata comprising B-pleurotergites, which would accord well with the two T-tergites and four B-pleurotergites seen in the
|
|
<typeStatus box="[723,868,967,1006]" pageId="4" pageNumber="297">holotype</typeStatus>
|
|
of
|
|
<emphasis box="[934,1161,967,1006]" italics="true" pageId="4" pageNumber="297">
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[934,1156,967,1006]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="malcolmi">M. malcolmi</taxonomicName>
|
|
.
|
|
</emphasis>
|
|
A ring-like tergite that overlies the prozonite of the anteriormost B-pleurotergite (and has processes permitting articulation of the T-tergite) in
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[750,961,1105,1144]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="malcolmi">
|
|
<emphasis box="[750,961,1105,1144]" italics="true" pageId="4" pageNumber="297">M. malcolmi</emphasis>
|
|
</taxonomicName>
|
|
is represented by only 4 of
|
|
<specimenCount box="[439,684,1151,1191]" pageId="4" pageNumber="297" type="generic">301 specimens</specimenCount>
|
|
of
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[741,906,1151,1191]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="angusi">
|
|
<emphasis box="[741,906,1151,1191]" italics="true" pageId="4" pageNumber="297">M. angusi</emphasis>
|
|
</taxonomicName>
|
|
and is unreported in the sample of
|
|
<taxonomicName baseAuthorityName="Tesakov & Alekseev" baseAuthorityYear="1992" box="[524,739,1197,1236]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="mirabilis">
|
|
<emphasis box="[524,739,1197,1236]" italics="true" pageId="4" pageNumber="297">M. mirabilis</emphasis>
|
|
</taxonomicName>
|
|
(
|
|
<figureCitation box="[769,896,1197,1236]" captionStart="Figure 2" captionStartId="5.[375,483,2155,2194]" captionTargetBox="[413,2080,498,2064]" captionTargetPageId="5" captionText="Figure 2. Relative abundances of different sclerite types at localities yielding Maldybulakia. (a) expected frequency of occurrence for M. malcolmi n.sp. based on one T-tergite, one ring tergite, four B-pleurotergites, and one caudal pleurotergite in articulated specimens. (b) sampled frequency of occurrence based on 223 disarticulated sclerites of M. malcolmi. (c) sampled frequency of occurrence based on 301 disarticulated sclerites of M. angusi n.sp. (d) sampled frequency of occurrence based on 44 disarticulated sclerites of M. mirabilis (Tesakov & Alekseev, 1992)." figureDoi="http://doi.org/10.5281/zenodo.4658419" httpUri="https://zenodo.org/record/4658419/files/figure.png" pageId="4" pageNumber="297">Fig. 2d</figureCitation>
|
|
). Given that each individual possesses one of this sclerite type it is underrepresented in the sample. Caudal tergites are significantly underrepresented, known from only two specimens.
|
|
</paragraph>
|
|
<paragraph blockId="4.[217,1210,414,3166]" pageId="4" pageNumber="297">
|
|
The relative abundance of disarticulated tergites in
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="malcolmi">
|
|
<emphasis italics="true" pageId="4" pageNumber="297">M. malcolmi</emphasis>
|
|
</taxonomicName>
|
|
differs from the 2:1 ratio of B:
|
|
<collectionCode box="[926,955,1473,1512]" name="Tavera, Department of Geology and Geophysics" pageId="4" pageNumber="297">T</collectionCode>
|
|
tergites in the sample of
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[393,559,1519,1558]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="angusi">
|
|
<emphasis box="[393,559,1519,1558]" italics="true" pageId="4" pageNumber="297">M. angusi</emphasis>
|
|
</taxonomicName>
|
|
as well as the 4:1 or 4:2 ratio predicted by articulated specimens (
|
|
<figureCitation box="[702,867,1565,1604]" captionStart="Figure 2" captionStartId="5.[375,483,2155,2194]" captionTargetBox="[413,2080,498,2064]" captionTargetPageId="5" captionText="Figure 2. Relative abundances of different sclerite types at localities yielding Maldybulakia. (a) expected frequency of occurrence for M. malcolmi n.sp. based on one T-tergite, one ring tergite, four B-pleurotergites, and one caudal pleurotergite in articulated specimens. (b) sampled frequency of occurrence based on 223 disarticulated sclerites of M. malcolmi. (c) sampled frequency of occurrence based on 301 disarticulated sclerites of M. angusi n.sp. (d) sampled frequency of occurrence based on 44 disarticulated sclerites of M. mirabilis (Tesakov & Alekseev, 1992)." figureDoi="http://doi.org/10.5281/zenodo.4658419" httpUri="https://zenodo.org/record/4658419/files/figure.png" pageId="4" pageNumber="297">Fig. 2a,b</figureCitation>
|
|
). Of disarticulated tergites of
|
|
<emphasis box="[425,665,1611,1650]" italics="true" pageId="4" pageNumber="297">
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[425,659,1611,1650]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="malcolmi">M. malcolmi</taxonomicName>
|
|
,
|
|
</emphasis>
|
|
185 are B-p1eurotergites (83 percent) and 28 are T-tergites (12.6 percent). The apparent over-abundance of B-tergites is at the expense of ring tergites (3.1 percent) and caudal tergites (1.3 percent). These differences between the three species, if not entirely due to differential transport of the various sclerite
|
|
<typeStatus box="[1108,1198,1840,1880]" pageId="4" pageNumber="297">types</typeStatus>
|
|
, might result from a greater number of T-tergites in
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="angusi">
|
|
<emphasis italics="true" pageId="4" pageNumber="297">M. angusi</emphasis>
|
|
</taxonomicName>
|
|
compared to
|
|
<emphasis box="[583,814,1933,1972]" italics="true" pageId="4" pageNumber="297">
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[583,809,1933,1972]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="malcolmi">M. malcolmi</taxonomicName>
|
|
.
|
|
</emphasis>
|
|
There is a significant taphonomic bias observed in the case of articulation. Articulated specimens of
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[679,901,2025,2064]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="malcolmi">
|
|
<emphasis box="[679,901,2025,2064]" italics="true" pageId="4" pageNumber="297">M. malcolmi</emphasis>
|
|
</taxonomicName>
|
|
are smaller than most of the disarticulated material, presumably because larger specimens did not survive transport intact.
|
|
</paragraph>
|
|
<paragraph blockId="4.[217,1210,414,3166]" pageId="4" pageNumber="297">
|
|
Although the trunk of
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[675,1045,2162,2202]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="angusi">
|
|
<emphasis box="[675,1045,2162,2202]" italics="true" pageId="4" pageNumber="297">Maldybulakia angusi</emphasis>
|
|
</taxonomicName>
|
|
displays much more serial variation than that of
|
|
<emphasis box="[933,1163,2208,2247]" italics="true" pageId="4" pageNumber="297">
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[933,1157,2208,2247]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="malcolmi">M. malcolmi</taxonomicName>
|
|
,
|
|
</emphasis>
|
|
it has proven possible to identify most tergites of the former according to their position in the latter, and it cannot be ruled out that
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[458,629,2346,2385]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="angusi">
|
|
<emphasis box="[458,629,2346,2385]" italics="true" pageId="4" pageNumber="297">M. angusi</emphasis>
|
|
</taxonomicName>
|
|
may possess the same number of tergites in the trunk as known for
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[838,1059,2392,2430]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="malcolmi">
|
|
<emphasis box="[838,1059,2392,2430]" italics="true" pageId="4" pageNumber="297">M. malcolmi</emphasis>
|
|
</taxonomicName>
|
|
(one or possibly two T-tergites, a ring tergite, four B-pleurotergites and a caudal tergite). The minimal number of tergites in
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[218,387,2529,2569]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="angusi">
|
|
<emphasis box="[218,387,2529,2569]" italics="true" pageId="4" pageNumber="297">M. angusi</emphasis>
|
|
</taxonomicName>
|
|
is discussed more fully after description of that species.
|
|
</paragraph>
|
|
<paragraph blockId="4.[217,1210,414,3166]" lastBlockId="4.[1277,2268,415,3166]" pageId="4" pageNumber="297">
|
|
<bibRefCitation author="Tesakov, A. S. & A. S. Alekseev" box="[268,788,2622,2661]" pageId="4" pageNumber="297" pagination="18 - 23" refId="ref13855" refString="Tesakov, A. S., & A. S. Alekseev, 1992. Myriapod-like arthropods from the Lower Devonian of central Kazakhstan. Paleontological Journal 26: 18 - 23." type="journal article" year="1992">Tesakov & Alekseev's (1992)</bibRefCitation>
|
|
evidence for regarding the B-pleurotergites of
|
|
<taxonomicName baseAuthorityName="Tesakov & Alekseev" baseAuthorityYear="1992" box="[690,1144,2668,2707]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="mirabilis">
|
|
<emphasis box="[690,1144,2668,2707]" italics="true" pageId="4" pageNumber="297">Maldybulakia mirabilis</emphasis>
|
|
</taxonomicName>
|
|
as diplosegmental (diplotergites) was their "distinct two-part structure". This refers to the separation of the anterior, articulating surface of the tergite from the posterior lobate part by a strong transverse groove or stricture. The Ttergites are of comparable proportions (length versus width) to the B-pleurotergites, and are also divided lengthwise by a transverse furrow in Australian species of
|
|
<emphasis box="[263,502,3035,3074]" italics="true" pageId="4" pageNumber="297">
|
|
<taxonomicName authorityName="Tesakov & Alekseev" authorityYear="1998" box="[263,497,3035,3074]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="genus">Maldybulakia</taxonomicName>
|
|
.
|
|
</emphasis>
|
|
This would suggest that they, too, would be diplotergites if the posterior trunk tergites were confirmed as being diplosegmental. All of the Palaeozoic myriapodous arthropods that might be compared with
|
|
<taxonomicName authorityName="Tesakov & Alekseev" authorityYear="1998" box="[1278,1508,461,499]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="genus">
|
|
<emphasis box="[1278,1508,461,499]" italics="true" pageId="4" pageNumber="297">Maldybulakia</emphasis>
|
|
</taxonomicName>
|
|
on the basis of tergite form have proven to be diplosegmental when the appendages became known. Examples are kampecarids (
|
|
<bibRefCitation author="Almond, J. E." box="[1769,2021,553,592]" pageId="4" pageNumber="297" refId="ref12168" refString="Almond, J. E., 1986. Studies on Palaeozoic Arthropoda. Unpublished Ph. D. thesis, University of Cambridge." type="book" year="1986">Almond, 1986</bibRefCitation>
|
|
), euphoberiid millipedes (
|
|
<bibRefCitation author="Burke, J. J." box="[1487,1710,599,638]" pageId="4" pageNumber="297" pagination="1 - 24" refId="ref12390" refString="Burke, J. J., 1979. A new millipede genus, Myriacantherpestes (Diplopoda, Archipolypoda) and a new species, Myriacantherpestes bradebirksi, from the English Coal Measures. Kirtlandia 30: 1 - 24." type="journal article" year="1979">Burke, 1979</bibRefCitation>
|
|
), and arthropleurids (
|
|
<bibRefCitation author="Briggs, D. E. G. & J. E. Almond" pageId="4" pageNumber="297" pagination="127 - 135" refId="ref12306" refString="Briggs, D. E. G., & J. E. Almond, 1994. The arthropleurids from the Stephanian (Late Carboniferous) of Montceau-Ies-Mines (Massif Central-France). In Quand le Massif Central Etait sous l'equateur: Un Ecosysteme Carbonijere d Montceaules-Mines, eds. C. Poplin & D. Helyer, pp. 127 - 135. Paris: Memoires de la Section des Sciences 12, Editions du Comite des Travaux Historiques et Scientifiques." type="journal article" year="1994">Briggs & Almond, 1994</bibRefCitation>
|
|
). It is thus likely that the trunk tagmata of
|
|
<taxonomicName authorityName="Tesakov & Alekseev" authorityYear="1998" box="[1278,1508,691,730]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="genus">
|
|
<emphasis box="[1278,1508,691,730]" italics="true" pageId="4" pageNumber="297">Maldybulakia</emphasis>
|
|
</taxonomicName>
|
|
are composed of diplosegments. The strong intertergal articulations and overlap of the prozonite of the B-pleurotergites by the preceding metazonite suggest that
|
|
<taxonomicName authorityName="Tesakov & Alekseev" authorityYear="1998" box="[1356,1586,829,868]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="genus">
|
|
<emphasis box="[1356,1586,829,868]" italics="true" pageId="4" pageNumber="297">Maldybulakia</emphasis>
|
|
</taxonomicName>
|
|
had the capacity to enroll.
|
|
</paragraph>
|
|
<paragraph blockId="4.[1277,2268,415,3166]" pageId="4" pageNumber="297">
|
|
A pair of articulated sclerites are preserved just behind the caudal pleurotergite of the
|
|
<typeStatus box="[1817,1961,921,960]" pageId="4" pageNumber="297">holotype</typeStatus>
|
|
of
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="malcolmi">
|
|
<emphasis italics="true" pageId="4" pageNumber="297">Maldybulakia malcolmi</emphasis>
|
|
</taxonomicName>
|
|
(Fig. 3a,g). They are also known from disarticulated specimens (Fig.
|
|
<quantity box="[1819,1865,1013,1052]" metricMagnitude="-3" metricUnit="kg" metricValue="4.0" pageId="4" pageNumber="297" unit="g" value="4.0">4g</quantity>
|
|
). Their positioning on the articulated specimen is a strong indication that they represent the posterior sclerites, although the nature of their (presumed) articulation to the caudal pleurotergite is not understood. Their small size, inferred posterior position, and overall structure invite a comparison with the telson of myriapods, which may also incorporate multiple sclerites (e.g., preanal sclerite or preanal ring, anal valves, and subanal plate in diplopods;
|
|
<bibRefCitation author="Enghoff, H." box="[1819,2191,1381,1420]" pageId="4" pageNumber="297" pagination="1 - 21" refId="ref12559" refString="Enghoff, H., 1990. The ground-plan of chilognathan millipedes (external morphology). In Proceedings of the 7 th International Congress ofMyriapodology, ed. A Minelli, pp. 1 - 21. Leiden: EJ. Brill." type="book chapter" year="1990">Enghoff, 1990: 14-15</bibRefCitation>
|
|
).
|
|
<emphasis bold="true" box="[2227,2261,1381,1420]" pageId="4" pageNumber="297">In</emphasis>
|
|
the descriptions below, these two sclerites are called telson sclerites.
|
|
</paragraph>
|
|
<paragraph blockId="4.[1277,2268,415,3166]" pageId="4" pageNumber="297">
|
|
Information on pleural morphology is supplied by
|
|
<emphasis box="[1277,1682,1565,1604]" italics="true" pageId="4" pageNumber="297">
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[1277,1677,1565,1604]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="malcolmi">Maldybulakia malcolmi</taxonomicName>
|
|
.
|
|
</emphasis>
|
|
The lateral exoskeletal component of
|
|
<taxonomicName authorityName="Tesakov & Alekseev" authorityYear="1998" box="[1327,1559,1611,1650]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="genus">
|
|
<emphasis box="[1327,1559,1611,1650]" italics="true" pageId="4" pageNumber="297">Maldybulakia</emphasis>
|
|
</taxonomicName>
|
|
is regarded as a mineralised part of the pleuron (i.e., pleurites), rather than the tergum (paratergites) because ofits marked topographic separation from the tergum. Alternative interpretations of pleural structures are addressed under discussion of
|
|
<emphasis box="[1870,2092,1795,1834]" italics="true" pageId="4" pageNumber="297">
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[1870,2087,1795,1834]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="malcolmi">M. malcolmi</taxonomicName>
|
|
.
|
|
</emphasis>
|
|
</paragraph>
|
|
<paragraph blockId="4.[1277,2268,415,3166]" lastBlockId="5.[212,1202,2536,3129]" lastPageId="5" lastPageNumber="298" pageId="4" pageNumber="297">
|
|
The lack of sampling of a head in the Australian occurrences is curious, given the abundance of trunk tergites known for both species.
|
|
<bibRefCitation author="Almond, J. E." box="[1837,2095,1933,1972]" pageId="4" pageNumber="297" refId="ref12168" refString="Almond, J. E., 1986. Studies on Palaeozoic Arthropoda. Unpublished Ph. D. thesis, University of Cambridge." type="book" year="1986">Almond (1986)</bibRefCitation>
|
|
observed that articulated heads were rare in the possibly allied kampecarids, even when the trunk was fully articulated, and attributed this to a delicate attachment by arthrodial membrane, as is the case in millipedes. The head tergite of
|
|
<taxonomicName authorityName="Page" authorityYear="1856" box="[1320,1522,2163,2202]" class="Archipolypoda" genus="Kampecaris" higherTaxonomySource="GBIF" kingdom="Animalia" pageId="4" pageNumber="297" phylum="Arthropoda" rank="genus">
|
|
<emphasis box="[1320,1522,2163,2202]" italics="true" pageId="4" pageNumber="297">Kampecaris</emphasis>
|
|
</taxonomicName>
|
|
is aratherfeatureless plate (orpair of plates, the second possibly a collum according to
|
|
<bibRefCitation author="Almond, J. E." box="[1996,2243,2209,2248]" pageId="4" pageNumber="297" refId="ref12168" refString="Almond, J. E., 1986. Studies on Palaeozoic Arthropoda. Unpublished Ph. D. thesis, University of Cambridge." type="book" year="1986">Almond, 1986</bibRefCitation>
|
|
). The narrow sclerite alleged to be the head of
|
|
<taxonomicName box="[2041,2262,2255,2294]" class="Arthropleuridea" family="Arthropleuridae" genus="Arthropleura" higherTaxonomySource="GBIF" kingdom="Animalia" order="Arthropleurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="genus">
|
|
<emphasis box="[2041,2262,2255,2294]" italics="true" pageId="4" pageNumber="297">Arthropleura</emphasis>
|
|
</taxonomicName>
|
|
(
|
|
<bibRefCitation author="Briggs, D. E. G. & J. E. Almond" box="[1290,1720,2301,2339]" pageId="4" pageNumber="297" pagination="127 - 135" refId="ref12306" refString="Briggs, D. E. G., & J. E. Almond, 1994. The arthropleurids from the Stephanian (Late Carboniferous) of Montceau-Ies-Mines (Massif Central-France). In Quand le Massif Central Etait sous l'equateur: Un Ecosysteme Carbonijere d Montceaules-Mines, eds. C. Poplin & D. Helyer, pp. 127 - 135. Paris: Memoires de la Section des Sciences 12, Editions du Comite des Travaux Historiques et Scientifiques." type="journal article" year="1994">Briggs & Almond, 1994</bibRefCitation>
|
|
: figs. 1, 2;
|
|
<bibRefCitation author="Brauckmann, C. & E. Gri & M. Thiele-Bourcier" pageId="4" pageNumber="297" pagination="179 - 192" refId="ref12265" refString="Brauckmann, C., E. Gri: ining & M. Thiele-Bourcier, 1997. Kopf- und Schwanz-Region von Arthropleura armata Jordan, 1854 (Arthropoda; Ober-Karbon). Geologica et Palaeontologica 31: 179 - 192." type="journal article" year="1997">
|
|
Brauckmann
|
|
<emphasis box="[2163,2261,2301,2339]" italics="true" pageId="4" pageNumber="297">et al.,</emphasis>
|
|
1997
|
|
</bibRefCitation>
|
|
) requires confirmation, as it may instead represent a collum-like tergite (W.A. Shear & H. Winkelmann, pers. comm., 1997). Even if the head of
|
|
<taxonomicName authorityName="Tesakov & Alekseev" authorityYear="1998" box="[1878,2109,2438,2477]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="genus">
|
|
<emphasis box="[1878,2109,2438,2477]" italics="true" pageId="4" pageNumber="297">Maldybulakia</emphasis>
|
|
</taxonomicName>
|
|
likewise involved a simple plate it is unlikely that it has been overlooked because sclerites of this sort were deliberately sought, yet no candidates have appeared. Heads likely underwent a different transport history than the trunk, perhaps because of a membranous attachment. The possibility that specimens such as the
|
|
<typeStatus box="[1991,2145,2714,2753]" pageId="4" pageNumber="297">holotype</typeStatus>
|
|
of
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="4" pageNumber="297" phylum="Arthropoda" rank="species" species="malcolmi">
|
|
<emphasis italics="true" pageId="4" pageNumber="297">M. malcolmi</emphasis>
|
|
</taxonomicName>
|
|
are complete, with the T-tergite being cephalic, is not favoured. This sclerite deviates from an expected morphology of an arthropod cephalon (e.g., lacking eyes or structures to accommodate them; lacking antennal sockets or notches), its transverse stricture and shape of the doublure conforming to a trunk diplotergite. The abrupt anterior termination of the doublure (
|
|
<figureCitation box="[1929,2052,3035,3074]" captionStart="Figure 6" captionStartId="10.[221,326,3025,3062]" captionTargetBox="[209,2257,404,2977]" captionTargetPageId="10" captionText="Figure 6. Maldybulakia malcolmi n.sp. Scale bars 10 mm. Ca) dorsal view of T-tergite AM F.102549. Cb) ventral view of T-tergite AM F.102550, showing doublure. (c) dorsal view of first B-pleurotergite AM F.102551. (d) dorsal view of first B-pleurotergite AM F.102552. (e) dorsal view of first B-pleurotergite AM F.102553. (j) dorsal view of B-pleurotergite AM F.102554. (g,h) dorsal and left lateral views of second B-pleurotergite AM F.102555. (i,j) right lateral and dorsal views of second B-pleurotergite AM F.102556." figureDoi="http://doi.org/10.5281/zenodo.4653168" httpUri="https://zenodo.org/record/4653168/files/figure.png" pageId="4" pageNumber="297">Fig. 6b</figureCitation>
|
|
) indicates a more anterior sclerite. The possibility that a species may possess two of these tergites further weakens the case for a cephalic identity. All of these factors outweigh the crude similarities in outline between a T-tergite and some arthropod head shields (e.g., the prosoma of bunodid xiphosurids, which has typical cephalic structures such as a cardiac lobe and ophthalmic ridges that are lacking in
|
|
<emphasis box="[214,477,2765,2804]" italics="true" pageId="5" pageNumber="298">
|
|
<taxonomicName authorityName="Tesakov & Alekseev" authorityYear="1998" box="[214,460,2765,2804]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="5" pageNumber="298" phylum="Arthropoda" rank="genus">Maldybulakia</taxonomicName>
|
|
).
|
|
</emphasis>
|
|
</paragraph>
|
|
<caption ID-DOI="http://doi.org/10.5281/zenodo.4658419" ID-Zenodo-Dep="4658419" httpUri="https://zenodo.org/record/4658419/files/figure.png" pageId="5" pageNumber="298" targetBox="[413,2080,498,2064]" targetPageId="5">
|
|
<paragraph blockId="5.[373,2106,2155,2399]" pageId="5" pageNumber="298">
|
|
Figure 2. Relative abundances of different sclerite types at localities yielding
|
|
<emphasis box="[1663,1950,2155,2194]" italics="true" pageId="5" pageNumber="298">
|
|
<taxonomicName authorityName="Tesakov & Alekseev" authorityYear="1998" box="[1663,1884,2155,2194]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="5" pageNumber="298" phylum="Arthropoda" rank="genus">Maldybulakia</taxonomicName>
|
|
. (a)
|
|
</emphasis>
|
|
expected frequency of occurrence for
|
|
<taxonomicName authority="Edgecombe, 1998" authorityName="Edgecombe" authorityYear="1998" box="[828,1024,2197,2236]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="5" pageNumber="298" phylum="Arthropoda" rank="species" species="malcolmi" status="n.sp.">
|
|
<emphasis box="[828,1024,2197,2236]" italics="true" pageId="5" pageNumber="298">M. malcolmi</emphasis>
|
|
</taxonomicName>
|
|
<taxonomicNameLabel box="[1040,1109,2197,2236]" pageId="5" pageNumber="298" rank="species">n.sp.</taxonomicNameLabel>
|
|
based on one T-tergite, one ring tergite, four B-pleurotergites, and one caudal pleurotergite in articulated specimens.
|
|
<emphasis box="[1273,1315,2239,2277]" italics="true" pageId="5" pageNumber="298">(b)</emphasis>
|
|
sampled frequency of occurrence based on 223 disarticulated sclerites of
|
|
<emphasis box="[767,1020,2280,2319]" italics="true" pageId="5" pageNumber="298">
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[767,962,2280,2319]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="5" pageNumber="298" phylum="Arthropoda" rank="species" species="malcolmi">M. malcolmi</taxonomicName>
|
|
. (c)
|
|
</emphasis>
|
|
sampled frequency of occurrence based on 301 disarticulated sclerites of
|
|
<taxonomicName authority="Edgecombe, 1998" authorityName="Edgecombe" authorityYear="1998" box="[418,578,2322,2361]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="5" pageNumber="298" phylum="Arthropoda" rank="species" species="angusi" status="n.sp.">
|
|
<emphasis box="[418,578,2322,2361]" italics="true" pageId="5" pageNumber="298">M. angusi</emphasis>
|
|
</taxonomicName>
|
|
<taxonomicNameLabel box="[594,664,2322,2361]" pageId="5" pageNumber="298" rank="species">n.sp.</taxonomicNameLabel>
|
|
<emphasis box="[683,725,2322,2361]" italics="true" pageId="5" pageNumber="298">(d)</emphasis>
|
|
sampled frequency of occurrence based on 44 disarticulated sclerites of
|
|
<taxonomicName authority="(Tesakov & Alekseev, 1992)" baseAuthorityName="Tesakov & Alekseev" baseAuthorityYear="1992" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="5" pageNumber="298" phylum="Arthropoda" rank="species" species="mirabilis">
|
|
<emphasis box="[1909,2104,2322,2361]" italics="true" pageId="5" pageNumber="298">M. mirabilis</emphasis>
|
|
(
|
|
<bibRefCitation author="Tesakov, A. S. & A. S. Alekseev" box="[384,810,2364,2399]" pageId="5" pageNumber="298" pagination="18 - 23" refId="ref13855" refString="Tesakov, A. S., & A. S. Alekseev, 1992. Myriapod-like arthropods from the Lower Devonian of central Kazakhstan. Paleontological Journal 26: 18 - 23." type="journal article" year="1992">Tesakov & Alekseev, 1992</bibRefCitation>
|
|
)
|
|
</taxonomicName>
|
|
.
|
|
</paragraph>
|
|
</caption>
|
|
<paragraph blockId="5.[212,1202,2536,3129]" lastBlockId="5.[1270,2261,2539,3129]" pageId="5" pageNumber="298">
|
|
A few disarticulated sc1erites do not conform to those in articulated specimens of
|
|
<emphasis box="[699,1124,2857,2897]" italics="true" pageId="5" pageNumber="298">
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[699,1118,2857,2897]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="5" pageNumber="298" phylum="Arthropoda" rank="species" species="malcolmi">Maldybulakia malcolmi</taxonomicName>
|
|
,
|
|
</emphasis>
|
|
and their position in the exoskeleton is unknown. A unique specimen of
|
|
<taxonomicName authorityName="Edgecombe" authorityYear="1998" box="[448,674,2949,2989]" class="Merostomata" family="Limulidae" genus="Maldybulakia" higherTaxonomySource="GBIF" kingdom="Animalia" order="Xiphosurida" pageId="5" pageNumber="298" phylum="Arthropoda" rank="species" species="malcolmi">
|
|
<emphasis box="[448,674,2949,2989]" italics="true" pageId="5" pageNumber="298">M. malcolmi</emphasis>
|
|
</taxonomicName>
|
|
(Fig.
|
|
<quantity box="[795,837,2949,2989]" metricMagnitude="-3" metricUnit="kg" metricValue="5.0" pageId="5" pageNumber="298" unit="g" value="5.0">5g</quantity>
|
|
,h) has a prominent, square embayment in could be presumed to be the posterior margin (this assuming that the strongly convex, ridge-like edge of the specimen is overlapped in articulation, as is the case for the prozonites). The conical median swelling warrants comparison with the caudal pleurotergite, although this swelling is strongly dorsally directed. The size and shape of the embayment invitespeculationthatthetelsonsclerites(Fig.
|
|
<quantity box="[2091,2135,2723,2765]" metricMagnitude="-3" metricUnit="kg" metricValue="4.0" pageId="5" pageNumber="298" unit="g" value="4.0">4g</quantity>
|
|
)might attach here. However, it does not seem possible that such a large, robust sc1erite could be positioned posteriorly in the trunk yet be missing from the
|
|
<typeStatus box="[2107,2259,2861,2902]" pageId="5" pageNumber="298">holotype</typeStatus>
|
|
and other articulated specimens. As such, it is more likely situated anterior to the T-tergites, but attempts to interpret it as a head are unconvincing, lacking any landmarks indicative of an arthropod cephalic shield or head capsule.
|
|
</paragraph>
|
|
</subSubSection>
|
|
</treatment>
|
|
</document> |