Temnospondyli Zittel, 1888

Sulej, Tomasz, Machalski, Marcin & Tałanda, Mateusz, 2024, New finds of Olenekian, Early Triassic, trematosaurid amphibians and prolocophonid reptiles from Poland, Acta Palaeontologica Polonica 69 (1), pp. 49-56 : 52-53

Order Temnospondyli Zittel, 1888 Family Trematosauridae Watson, 1919 Trematosauridae gen. et sp. indet.

Figs. 2 , 3B .

Material.—ZPAL V. 78/3, parasphenoid from lower Olenekian (Lower Triassic) of Stryczowice, north-eastern margin of the Holy Cross Mountains, Poland.

Description.—An almost complete parasphenoid ZPAL V. 78/3 is preserved in a conglomerate slab in two pieces (part and counterpart) with the bone visible in cross-section ( Fig. 2 ). The anterior part of cultriform process and the left part of the parasphenoid plate are broken ( Fig. 3B 1 ).

A large area for the exoccipital is visible on the posterolateral corner of the dorsal side. It has a similar shape, size and texture to those of Inflectosaurus amplus Shishkin, 1960 (PIN 953/100; Shishkin 1968; Novikov 2007). The posterior part is divided on three belts by distinct ridges. The opening for the intracranial branch of the internal carotid is located more anteriorly than in Trematosaurus brauni Burmeister, 1849 ( Schoch 2019) and Inflectosaurus amplus ( Shishkin 1968; PIN 953/100). The posterior aspect of the pterygoid area is not visible in dorsal view, unlike in Inflectosaurus amplus ( Shishkin 1968; PIN 953/100). The entrance foramen for the palatine nerve, which is also the exit for the posterior branch of the palatine artery, is well visible only in Inflectosaurus amplus (PIN 953/100). This foramen is much larger in Trematosaurus galae Novikov, 2010 ( Novikov 2010: fig. 1d) and has a large ornamented area, which is absent in the new Polish specimen.

The long, irregular area for suture with the pterygoid is well visible on the ventral side of the parasphenoid plate. Its ventral edge is bent inwards ( Fig. 3 ) as in Trematosaurus brauni ( Schoch 2019) . The posterior edge of the parasphenoid plate is slightly bent inwards, similar to Inflectosaurus amplus ( Novikov 2007) . A small opening is visible in the central area of the parasphenoid plate, which was not reported in any trematosaurid so far.

The cultriform process is T-shaped in cross-section with shallow grooves on both sides. Its ventral and lateral edges are sharp. This morphology is very similar to that observed in Trematosaurus brauni ( Schoch 2019) and unlike Angusaurus Getmanov, 1989 , which has a very narrow cultriform process ( Fernández-Coll et al. 2019). The posterior aspect of the lateral edge of the cultriform process is slightly convexly curved compared to the same feature in Trematosaurus brauni and Inflectosaurus amplus , which is strongly curved.

Remarks.—The Germanic Basin trematosaurids were originally described based on material from two localities: Merkel’s Quarry and Kappel in the Black Forest, Germany ( Schoch and Werneburg 1998; Schoch and Milner 2000). Up until 2009, the geographically closest sites to the Holy Cross Mountains that yielded termatosaurid material were in Eastern Europe ( Shishkin 1968; Novikov 2007, 2010). Sulej and Niedźwiedzki (2009) then reported the first trematosaurid from Poland from the Wióry locality, dated as Olenekian (Early Triassic). Later, Sulej and Niedźwiedzki (2013) described the capitosauroid Parotosuchus ptaszynski Sulej & Niedźwiedzki, 2013 , from the same locality, based on frag- ments of a cranium and mandible. Globally, trematosaurids are also known from Middle and Late Triassic-aged deposits from Madagascar ( Lehman 1966, 1979) and South Africa ( Watson 1919; Welles 1993; Shishkin and Welman 1994).

Figures

Fig. 2. Parasphenoid of Trematosauridae gen. et sp. indet. from Lower Triassic of Stryczowice, Holy Cross Mountains, Poland. ZPAL V.78/3, reconstruc- tion in dorsal (A1), ventral (A2), and lateral (A3) views, original specimen, part and counterpart (A4, A5). The restoration was based on the CT scan by supplementing the missing fragment with a mirror image of the preserved part (Fig. 3B).

Fig. 3. Comparison of the parasphenoid of Trematosauridae gen. et sp. indet. with specimens from Germany and Russia. A. Trematosaurus brauni Burmeister, 1849, Merkel’s Quarry, Germany,?late Olenekian, MSB G 366 in ventral view (modified from Schoch 2019: fig. 7B). B. Trematosauridae gen. et sp. indet., Stryczowice, Holy Cross Mountains, Poland, early Olenekian{?}, ZPAL V. 78/3 in ventral (B1) and dorsal (B1) views. C. Inflectosaurus amplus Shishkin, 1960, Bolshoe Bogdo locality, late Olenekian, PIN 953/100 in dorsal view (modified from Shishkin 1968: fig. 2c).

Fig.1. The geological setting of the vertebrate-bearing locality at Stryczowice.A. Location of the Holy Cross Mountains in Poland.B. Simplified geological map of the Holy Cross Mountains with Paleozoic core and range of the Bundsandstein exposures. C. Location of the Stryczowice locality on the geological map of the north-eastern margin of the Holy Cross Mountains with Paleozoic deposits, continental mass flow-conglomerates traditionally referred to as the “Zechstein”, Buntsandstein, and younger deposits. D. Log of the Stryczowice quarry with location of the bone-bearing basal conglomerate marked by a black arrow, and location of the levels with arthropod trackways marked by white arrows; numbers 1–5 mark units discussed in text. Figure adopted from Machalski and Machalska 1994: fig. 1.