Striatochelys baba Massonne, Augustin, Matzke & Bohme, 2023, sp. nov.
Creators: name: Massonne, Tobias
name: Augustin, Felix J.
name: Matzke, Andreas T.
name: Bohme, Madelaine
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Cypriniformes
Cyprinidae
Striatochelys
Striatochelys baba

description: Striatochelys baba sp. nov.
(Figs 2–7)
Diagnosis. Striatochelys baba can be differentiated from Striatochelys impressa comb. nov. by the combination of the following characters: (1) a larger costal VIII, forming the posterolateral margin of the carapace; (2) presence of ridges on the neurals, which are straight anteriorly and sinusoidal posteriorly; and (3) entoplastron callosity in the shape of a bulge (unknown for S. impressa and possibly a synapomorphy for S. baba + S. impressa).
Etymology. The species name is derived from the Vietnamese word ‘Ba ba’, meaning softshell turtle, declared as substantive.
Holotype. GPIT-PV-112860, carapace, xiphiplastron, thoracic vertebrae (GPIT-PV-112860-1) and partial plastron (entoplastron, GPIT-PV-112860-2; hyoplastron right, GPIT-PV-112860-3; hyoplastron left, GPIT-PV-112860-4; hypoplastron right, GPIT-PV-112860-5) and further postcranial material (cervical vertebra, GPIT-PV-112860-6; left pectoral girdle, GPIT-PV-112860-7; left humerus, GPIT-PV-112860-8; right radius, GPIT-PV-112860-9; right ulna, GPIT-PV-112860-10; phalanx, GPIT-PV-112860-11).
Referred material. Additional material consists of: a nearly complete carapace missing only the nuchal with a right hyo- and hypoplastron (GPIT-PV-122867); a fragmentary carapace with a complete row of neurals and a nuchal (GPIT-PV-122879); the anterior part of a carapace associated with an entoplastron (GPIT-PV-122872); fragmented costals belonging to a larger individual (GPIT-PV-122875); fragmented costals and a right hypoplastron (GPIT-PV-122871); a costal fragment (GPIT-PV-122874); a medial part of a hypoplastron (GPIT-PV-122873); an anterior part of the carapace and right hyo- and hypoplastron (GPIT-PV-112861); a part of the carapace and plastron and a first thoracic vertebra (GPIT-PV-112862 and GPIT-PV-112863); multiple isolated costal fragments belonging to a single individual (GPIT-PV-112864); multiple carapace fragments belonging to a single individual (GPIT-PV-112865); left xiphiplastron and a right costal VIII (GPIT-PV-112866); and a single costal fragment (GPIT-PV-112867).
Additionally, an isolated pectoral girdle (GPIT-PV-122869) and skull (GPIT-PV-122870) putatively belonging to a single individual of a pan-trionychid turtle, as well as additional postcranial material consisting of an isolated costal fragment (GPIT-PV-122877), a phalanx (GPT-PV-122878) and a plastron fragment (GPIT-PV-112868) are tentatively referred to S. baba.
Type locality and horizon. The fossils were recovered from the base of layer 80 of the Na Duong coal mine (Bohme et al., 2013) in northern Vietnam (21 Ǫ 42.2 ĮN, 106 Ǫ 58.6 ĮE); Na Duong Formation, Eocene, late Bartonian–Priabonian age (39–35 Ma).
Remarks. The holotype carapace of S. baba was embedded with its ventral part facing upwards. This allowed for a negative relief of the dorsal carapace, especially the ridges, in the sediment below. Based on those ridges, a cast was modelled for the missing posterior most part, but does not cover the correct outline, as seen in the posteriorly complete specimen GPIT-PV-122867.
description: Published as part of Massonne, Tobias, Augustin, Felix J., Matzke, Andreas T. & Bohme, Madelaine, 2023, A new cryptodire from the Eocene of the Na Duong Basin (northern Vietnam) sheds new light on Pan-Trionychidae from Southeast Asia, pp. 1-25 in Journal of Systematic Palaeontology (2217505) (2217505) 21 (1) on pages 4-6, DOI: 10.1080/14772019.2023.2217505, http://zenodo.org/record/10883757