Fossil decapods from the Upper Quaternary in Shinjima Island in Kagoshima Kyushu, Japan, and description of a new species of ghost shrimp (Axiidea Eucalliacidae) Author Ando, Yusuke Mizunami Fossil Museum, 1 - 47 Yamanouchi, Akeyo-cho, Mizunami City, Gifu 509 - 6132, Japan Author Kawano, Shigenori Tochigi Prefectural Museum, 2 - 2 Mutsumi-cho, Utsunomiya City, Tochigi 320 - 0865, Japan. Author Muramiya, Yusuke Fukada Geological Institute, 2 - 13 - 12 Honkomagome, Bunkyo-ku, Tokyo 113 - 0021, Japan. Author Niiyama, Sota 0000-0002-7141-1072 Graduate School of Science and Technology, Kanazawa University, Kakuma, Kanazawa City, Ishikawa 920 - 1192, Japan. niiyama @ stu. kanazawa-u. ac. jp; https: // orcid. org / 0000 - 0002 - 7141 - 1072 niiyama@stu.kanazawa-u.ac.jp Author Kameyama, Sohiko 0000-0002-7104-1841 Graduate School of Environmental Science, Hokkaido University, Kita-ku, Sapporo City, Hokkaido 060 - 0810, Japan. skameyama @ ees. hokudai. ac. jp; https: // orcid. org / 0000 - 0002 - 7104 - 1841 skameyama@ees.hokudai.ac.jp Author Shimoyama, Shoichi 0000-0002-2393-0820 Faculty of Science and Engineering, Saga University, 1 Honjo-machi, Saga City, Saga 840 - 8502, Japan. cshmym @ diary. ocn. ne. jp; https: // orcid. org / 0000 - 0002 - 2393 - 0820 cshmym@diary.ocn.ne.jp text Zootaxa 2020 2020-11-16 4878 3 523 541 journal article 7925 10.11646/zootaxa.4878.3.5 c176c1fb-0892-4318-827a-9506b774cf2a 1175-5326 4425380 459CF462-A542-4C4D-8238-43C637D9BC34 Calliax nishiki sp. nov. [New Japanese name: Nishiki-suna-moguri] ( Figs. 3 , 4 ) urn:lsid:zoobank.org:act: 93ECF222-E117-43E9-8330-755E841C2983 Material examined. MFM142024 ( holotype : P1 chela) , MFM142025 ( paratype : P1 chela) , MFM142026 ( paratype : P1 chela) , MFM142027 ( paratype : P1 chela) , MFM142028 ( paratype : P1 chela) , MFM142029 ( paratype : P1 chela) , MFM142030 ( paratype : P1 chela) , MFM142031 ( paratype : P1 dactylus) , MFM142032 ( paratype : P1 dactylus) , MFM142033 ( paratype : P1 dactylus) , MFM142034 ( paratype : P1 carpus) , MFM142035 ( paratype : P1 carpus) , MFM142036 ( paratype : P1 carpus) , MFM142037 ( paratype : P1 carpus, merus, ischium) , MFM142038 ( paratype : P1 merus) , MFM142039 ( paratype : P1 merus) , MFM142040 ( paratype : P1 merus) , MFM142041 ( paratype : P1 ischium) , MFM142042 ( paratype : P1 ischium) and 112 referred specimens . Etymology. The name is derived from “Nishiki”, a Japanese word meaning beautiful, because of the fine preservations of the present specimens. Type locality. Loc. 2-1, Moeshima Silt Bed in Shinjima Island , Kagoshima City , Kagoshima Prefecture , Japan . Holocene . Measurements. See Table 2 . Diagnosis. Moderately sized axioid. Ischium of pereiopod 1 (P1) long, slender. Merus of P1 2.5 times longer than high; lower margin covered with small tubercles; posterior part of lower margin bearing 3–5 slender, sharp, slightly curved spines. Carpus of P1 1.3 times higher than long; proximo-upper margin concave; lower margin well curved without tubercles. Palm of Pl subrectangular, 2.2 times longer than tall; lateral outer surface of anterior margin (1/3 of palm height) armed with a slender keel-like ridge extending to half-length of dorsal border of fixed finger; base of ridge bearing 1–3 tubercles; outer surface of anterior part of proximo-lower margin with 10–15 small tubercles; lower margin keeled, slightly curved anteriorly. Fixed finger of P1 approximately 30 percent of length of palm, triangular, elongate, strongly curved dorsally and inner laterally with acutely pointed tip; occlusal margin armed with 2–3 molar-like triangular teeth. Dactylus of P1 as long as fixed finger, triangular, elongate, strongly curved dorsally and inner laterally with acutely pointed tip; occlusal margin bearing 8–10 small, rounded denticles.

Species/Locality	Moeshima Silt Bed		Moeshima Shell Bed
Loc. 1-1	Loc. 1-2	Loc. 2-1	Loc. 2-2	Loc. 1-3	Loc.2-3	Loc. 3-1
Laticallichirus grandis ( Karasawa & Goda, 1996 )	>200	>200	>200
Calliax nishiki sp. nov.	4	6	102	19
Paguridae gen. et sp. indet.	3	5	2
Pagurus cf. megalops (Stimpson, 1858)	3
Munida sp.	2
Tymolus uncifer ( Ortmann, 1892 )	1	5	1
Ebalia tuberculosa (A. Milne Edwards, 1873)	8
Myra sp.	2
Philyra cf. syndactyla Ortmann, 1892	1
Majidae gen. et sp. indet.	1
Leptomithrax sp.	1
Romaleon sp.	1
Podocatactes hamifer Ortmann, 1893	2
Charybdis sp.	8	23	11
Carcinoplax longimana (de Haan, 1833 )	1	1	29	1

FIGURE 3 . Calliax nishiki sp. nov. A, MFM142024, holotype, P1 left chela; A 1 , outer lateral view; A 2 , inner lateral view; A 3 , upper view; A 4 , lower view. B, MFM142025, paratype, P1 left chela; B 1 , outer lateral view; B 2 , inner lateral view; B 3 , upper view; B 4 , lower view. C, MFM142026, paratype, P1 right chela, outer lateral view. D, MFM142027, paratype, P1 left chela, outer lateral view. E, MFM142028, paratype, P1 right chela, outer lateral view. F, MFM142029, paratype, P1 right chela, outer lateral view. G, MFM142030, paratype P1 right chela, outer lateral view. H, MFM142031, paratype, P1 right dactylus; H 1 , outer lateral view; H 2 , inner lateral view; H 3 , upper view; H 4 , lower view. I, MFM142032, paratype, P1 left dactylus; I 1 , outer lateral view; I 2 , inner lateral view; I 3 , upper view; I 4 , lower view. J, MFM142033, paratype, P1 right dactylus; J 1 , outer lateral view; J 2 , inner lateral view; J 3 , upper view; J 4 , lower view. K, MFM142034, paratype, P1 left carpus, outer lateral view. L, MFM142035, paratype, P1 right carpus, outer lateral view. M, MFM142036, paratype, P1 left carpus, outer lateral view. N, MFM 142037, paratype, P1 left carpus, merus and ischium, outer lateral view. O, MFM142038, P1 right merus, outer lateral view. P, MFM142039, P1 left merus, outer lateral view. Q, MFM142040, P1 right merus, outer lateral view. R, MFM142041, P1 right ischium, outer lateral view. S, MFM142042, P1 right ischium, outer lateral view. All scale bars indicate 1.0 mm. TABLE 2 . Measurements (mm) of Calliax nishiki sp. nov. Abbreviations: L. length; H, height.

Specimens	Parts	L (mm)	H (mm)
MFM142024	Palm and fixed finger (P1)	14.4	6.3
MFM142025	Palm and fixed finger (P1)	13.5	6.1
MFM142026	Palm and fixed finger (P1)	12.9	6.1
MFM142027	Palm and fixed finger (P1)	17.2	7.8
MFM142028	Palm and fixed finger (P1)	12.2	5.3
MFM142029	Palm and fixed finger (P1)	16.0	6.9
MFM142030	Palm and fixed finger (P1)	18.7	7.7
MFM142031	Dactylus (P1)	8.1	3.2
MFM142032	Dactylus (P1)	7.1	2.5
MFM142033	Dactylus (P1)	5.0	2.1
MFM142034	Carpus (P1)	5.6	7.3
MFM142035	Carpus (P1)	3.1	4.1
MFM142036	Carpus (P1)	5.7	7.9
MFM142037	Merus (P1)	8.7	3.2
MFM142038	Merus (P1)	8.5	2.9
MFM142039	Merus (P1)	6.7	2.6
MFM142040	Merus (P1)	6.4	2.6
MFM142041	Ischium (P1)	8.1	2.9
MFM142042	Ischium (P1)	6.2	2.1

Description . Moderately sized axioid. Ischium of pereiopod 1 (P1) long, slender; upper margin unarmed; lower margin bearing 10–15 small rounded spines. Merus of P1 2.5 times longer than tall; upper margin slightly sinuous; lateral outer surface with one ridge which is slightly sinuous; lower margin covered with 20–40 small tubercles along its length; posterior part of lower margin bearing 3–5 slender, sharp, slightly curved spines. Carpus of P1 as long as merus, 1.3 times higher than long; upper margin slightly curved, unarmed; proximo-upper margin concave; proximo-lower margin rounded, strongly curved and smooth its outline; lower margin well-curved without tubercles. Palm of Pl subrectangular, about 2.5 times longer than carpus, 2.2 times longer than high; upper margin slightly curved, converging distally, unarmed; outer surface of upper margin smooth; lateral outer surface of anterior margin (1/3 of palm height) armed with slender keel-like ridge extending to half-length of dorsal border of fixed finger; base of ridge bearing 1–3 tubercles; outer surface of anterior part of proximo-lower margin with 10–15 small tubercles; lower margin keeled, slightly curved anteriorly. Fixed finger of P1 approximately 30 percent of length of palm, triangular, elongate, strongly curved dorsally and inner laterally with acutely pointed tip; near base of fixed finger swollen; occlusal margin armed with 2–3 molar-like triangular teeth; lateral inner surface armed with one ridge along base to middle of fixed finger; base of inner ridge also bearing 1–3 tubercles; anterior part of inner surface with one low, short ridge; lower margin curved, unarmed. Dactylus of P1 as long as fixed finger, triangular, elongate, strongly curved dorsally and inner laterally with acutely pointed tip; upper margin well-curved; lateral outer surface smooth; lateral inner surface armed with ridge along its length; occlusal margin bearing 8–10 low rounded denticles. Remarks. The present species is closest to extant Calliax lobata (de Gaillande & Langardère, 1966) , first described from southern France (Mediterranean). However, the latter species has seven blunt spines on the lower margin of the merus, single molar-like triangular teeth on the occlusal margin of the fixed finger and an absence of tubercles on the lateral surface of the palm. The new species is similar to extant Calliax doerjesti Sakai, 1999 , described from the USA , but differs in having 3–5 spines on the lower margin of the merus, a longer carpus with more rounded proximo-lower margin and 2–3 molar-like, triangular teeth on the occlusal margin of the fixed finger. The present species also resembles Calliax michelottii (A. Milne-Edwards, 1860 ) first described from the Miocene of Italy ( Hyžný & Gašparič 2014 ), but differs in having 3–5 spines on the lower margin of the merus, only one ridge on the lateral surface of base of fixed finger and a longer palm. García Raso et al . (2019) reported extant Calliax lobata from the bathyal bottom of a reducing environment, and Taviani et al . (2013) collected many unnamed specimens of Calliax from the Holocene deposits, which were formed under the bathyal bottom within a similar setting. Moreover, Hyžný & Gašparič (2014) showed that many specimens identified with Calliax michelottii were collected from Oligocene to Miocene deposits formed at bathyal depths. Therefore, the present new Calliax might also be abundant in deep, marine, reducing environments. Indeed, this genus seems to mainly occur in reducing environments deeper than the sublittoral zone.