Towards a unifying systematic scheme of fossil and living billfishes (Teleostei, Istiophoridae) Author Gracia, Carlos De Department of Palaeontology, Faculty of Earth Sciences, Geography and Astronomy, University of Vienna, Josef Holaubek Platz 2 (UZA II) / 2 A 323, 1090, Vienna, Austria; & Vienna Doctoral School of Ecology and Evolution (VDSEE), University of Vienna, Vienna, Austria; & Smithsonian Tropical Research Institute, Box 0843 - 03092, Balboa, Ancon, Panama, Republic of Panama; Author Correa-Metrio, Alex Centro de Geociencias, Universidad Nacional Autonoma de M ́ exico, Campus Juriquilla, Quer ́ etaro 76230, Mexico; & Instituto de Geolog ́ ıa, Universidad Nacional Autonoma de M ́ exico, Ciudad Universitaria, 04510, M ́ exico, D. F., Mexico; Author Carvalho, Monica Smithsonian Tropical Research Institute, Box 0843 - 03092, Balboa, Ancon, Panama, Republic of Panama; Author Velez-Juarbe, Jorge Department of Mammalogy, Natural History Museum of Los Angeles Country, 900 Exposition Boulevard, Los Angeles, CA 90007, USA; & Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA; Author P ̆ rik, Tom ́ a ̆ s Author , Carlos Jarami Author Kri, nd Jurgen text Journal of Systematic Palaeontology 2022 2091959 2022-08-19 20 1 1 36 http://dx.doi.org/10.1080/14772019.2022.2091959 journal article 10.1080/14772019.2022.2091959 1478-0941 :pub:D3D3B15B-36FA-42EB-98AD-FAF369D † Spathochoira calvertense ( Berry, 1917 ) comb. nov. ( Figs 7B , 8A , 9J, K ) 1917 † Istiophorus calvertensis Berry : 461, figs 1, 2. 1987 † Pseudohistiophorus calvertensis (Berry) , Schultz: 120, tab. 2. 1990 † Makaira calvertensis (Berry) ; Fierstine: 15, tab. 2. Diagnosis. This taxon is characterized by the following combination of morphological traits (an asterisk indicates autapomorphic traits): a sub-cylindrical and anteriorly gradually tapering rostrum with extremely large internal canals and that are oval in cross-section in the most distal part; in having a concave ventral margin in the anterior two-thirds forming a pronounced ventral canal along the whole length of rostrum resulting in a cross-sectional shape reminiscent of a pig nose at 0.5 L $; prenasals that terminate close to distal tip$. Holotype . USNM 9344, a 310 mm long distal rostral fragment. Occurrence. Late Miocene, Eastover Formation, Tar Bay, James River, Virginia , USA (see also Fierstine 1998 , 2001 , 2006 ). Remarks. † Spathochoira calvertensis gen. nov. is a 310 mm long distal fragment of a rostrum that is dorsally covered by poorly preserved denticles at 57.3 mm from its distal tip ( Fierstine 1998 , 2001 ). The rostrum is sub-cylindrical in cross-section, tapering gradually until the cross-section becomes oval in outline towards the most distal part ( Berry 1917 ) ( Fig. 8A ). The distal tip is slender and resembles that of Istiompax indica ( Fig. 7I ). There are two grooves on the dorsal surface that represent the sutures for prenasals ( Fig. 8A ). These grooves decrease gradually distally until they disappear completely near the distal tip (P distance) ( Berry 1917 ). The ventral surface of the rostrum is concave in its anterior two thirds and there is a pronounced median suture that forms a distinct canal identifiable along the whole length of the rostrum ( Berry 1917 ) ( Figs 8A , 9J, K ). The rostrum is broken proximally and the transversal fracture represents the 0.5 L distance ( Fig. 9J ) ( Fierstine 2001 ). A pair of large internal canals is visible ( Table 3 ), which are located at 11.0 mm from the dorsal surface of the rostrum (DD1 distance) ( Fig. 9J ). The internal canals are very large based on their proportion relative to the rostral depth (D1) (Table 4). The position of the canals ( Fig. 9J, K ) is medial and they have a central · Figure 5. A – C , G–I, † Morgula donosochagrense gen. et sp. nov. , holotype (MUPAN–STRI31293); A , rostrum dorsal view; B, rostrum left lateral view; C , rostrum ventral view; G–I, lower jaw showing articulate dentaries; G, ventral view; H, dorsal view; I, disarticulated right partial dentary in lateral view showing the interdentary joint and the mandibular foramen. D–F, † Makaira fierstini sp. nov. , holotype , USNM 358534; D, rostrum dorsal view; E, rostrum ventral view; F, detail of the right lateral view of the rostrum at its proximal end. Missing parts of the bone are indicated by dash-lines. Abbreviations: mf, mandibular foramen; N , nasal; PM , premaxilla; PN , prenasal. Scale bars: A –F = 10 cm , G–I = 5 cm . Figure 6. A, B, † Morgula donosochagrense gen et sp. nov. (MUPAN–STRI31293); A, cross-section at 0.5 L; B, cross-section at 0.25 L. C, D, † Makaira colonense sp. nov. (MUPAN–STRI39292); C, cross-section at 0.5 L; D, cross-section at 0.25 L. Abbreviation: PN , prenasal. Scale bars = 1 cm. arrangement following our terminology (Supplemental material Fig. S2). The canals are levogyres (Supplemental material Fig. S2I) rotated about 40 ǫ , they are wider inferiorly and separated from each other by 1.0 mm ( Berry 1917 ). In the midline suture, c . 7.0 mm dorsomedial to the canals, a central oblanceolate foramen with a 1.0 mm diameter is present ( Fig. 9J ) ( Berry 1917 ; Fierstine 2001 ). The cross-section at 0.25 L for this specimen was studied with the help of CT scans and estimated to be 134 mm from the distal tip ( Fierstine 1998 , 2001 ) ( Fig. 9K ). The CT results show that the rostrum is oval, the ventral convexity is visible, and the internal canals are ovals and proportionately large ( Fig. 9J, K ). The internal canals at this position are in a medial position, centrally arranged and are 5.72 mm height (H2), 3.29 mm wide (N2) and are separated by 2.0 mm bone ( Fierstine 1998 , 2001 ) ( Fig. 9K , Supplemental material 1).