Joyce Walter G, Bandyopadhyay Saswati
Department of Geosciences, University of Fribourg, Fribourg, Switzerland.
Geological Studies Unit, Indian Statistical Institute, Kolkata, India.
PeerJ. 2020 Feb 11;8:e8542. doi: 10.7717/peerj.8542. eCollection 2020.
is an extinct turtle from the Early to Middle Jurassic Kota Formation of the Pranhita-Godavari Gondwana basin, India. The holotype and previously only known specimen is a partially eroded shell that had been collected near Kota village, north of Sironcha, in Maharashtra State. Phylogenetic analyses have consistently suggested placement at the base of the clade Mesochelydia.
We here figure and describe the holotype of and two new specimens, which were collected from the Kota Formation near Kistapur village, Telengana State, about 60 km NW from the type locality. We furthermore explore the relationships of this fossil turtle by updating its scoring based on all available material in the most recent analysis of basal turtle relationships.
The revision of the holotype of provides minor adjustments to the morphology of this specimen, in particular recognition of a transverse break across the carapace, presence of only eight neurals, of which the eight is octagonal, and presence of a pathological element located between neurals VII and VIII. The new material provides new anatomical insights, in particular presence of a broad cervical, a vertebral V that inserts deeply into vertebral IV, narrow pleurals within increasingly short posteromedial contacts with the vertebrals towards the posterior, at least three pairs of musk duct foramina, and numerous insights into the morphology of the girdles and stylopodium. In combination, all material allows affirming the validity of with confidence. The phylogenetic analysis affirms the placement of as a basal mesochelydian, but cannot resolve its relationships relative to the roughly coeval and .
是一种已灭绝的龟类，来自印度普拉尼塔 - 戈达瓦里冈瓦纳盆地早侏罗世至中侏罗世的科塔组。其正模标本也是此前唯一已知的标本，是一个部分侵蚀的龟壳，在马哈拉施特拉邦锡龙查以北的科塔村附近采集到。系统发育分析一直表明它处于中龟亚目分支的基部。
我们在此展示并描述了的正模标本以及两个新标本，这些标本是从特伦甘纳邦基斯塔普尔村附近的科塔组采集的，距离模式产地西北约60公里。我们还通过在最近一次关于基干龟类关系的分析中基于所有可用材料更新其特征评分，来探究这种化石龟的亲缘关系。
对的正模标本的修订对该标本的形态进行了细微调整，特别是识别出背甲上的一条横向裂缝、仅存在八块椎板（其中第八块是八角形）以及在椎板VII和VIII之间存在一个病理元素。新材料提供了新的解剖学见解，特别是存在宽阔的颈部、深深插入椎板IV的椎板V、向后与椎板的后内侧接触越来越短的狭窄肋板、至少三对麝香管孔，以及对腰带和肢骨形态的众多见解。综合起来，所有材料都能确定的有效性。系统发育分析肯定了作为基干中龟亚目的位置，但无法解析它相对于大致同时期的和的亲缘关系。
