Proganochelys quenstedtii Baur, 1887

Sues, Hans-Dieter & Schoch, Rainer R., 2025, Synopsis of the Triassic reptiles from Germany, Fossil Record 28 (2), pp. 411-483 : 411-483

Proganochelys quenstedtii Baur, 1887

Holotype.

GPIT-PV -30000 , steinkern of shell.

Type locality.

Neuenhaus (= Häfner-Neuhausen), Baden-Württemberg.

Type horizon.

Middle or Upper Stubensandstein (S 2-4), Löwenstein Formation, Middle Keuper Subgroup. Age: Late Triassic (Norian: Alaunian-Sevatian).

Referred material.

See Gaffney (1990).

Diagnosis.

Distinguished by the following autapomorphies: basioccipital with ventral tubercle; presence of tail club formed by fused caudal osteoderms; and phalangeal formulae for manus and pes 2-2 - 2 - 2 - 2 ( Gaffney 1990; Fig. 14 B ). Joyce (2017) listed various features distinguishing Proganochelys quenstedtii from other known stem-turtles.

Comments.

The holotype of Proganochelys quenstedtii was also designated as the holotype of Psammochelys keuperiana Quenstedt, 1889 , rendering the latter binomen an objective junior synonym of the former. Jaekel (1914, 1918 a) described specimens of this species from the upper part of the Arnstadt Formation of the Baerecke-Limpricht brick-clay pit near Halberstadt ( Lower Saxony) using the binomen Stegochelys dux . He subsequently changed the genus name to Triassochelys because Stegochelys was already taken ( Jaekel 1918 b). Gaffney (1985, 1990) documented the osteology of Proganochelys quenstedtii in detail.

References.

Baur (1887), Quenstedt (1889), E. Fraas (1899), Jaekel (1914, 1918 a, b), Gaffney (1985, 1990), Joyce (2017).

Figures

Figure 14. Reptiles from the Middle Keuper Subgroup. A. Stem-turtle Proterochersis robusta (SMNS 17561), shell. Length 30 cm. B. Stem-turtle Proganochelys quenstedtii (SMNS), reconstructed skeleton including shell. C. Lepidosauromorph Elachistosuchus huenei, holotype (MB. R. 4520), incomplete skull in lateral and dorsal view. Scale bar: 1 cm. D. Sphenodontian rhynchocephalian Parvosaurus harudensis, holotype (MB. R. 4520.2), CT-based rendering of incomplete skull in dorsal view. Scale bar: 5 mm. From Freisem et al. (2024) – CC-BY 4.0.