Tomasz Sulej

A dicynodont-theropod association in the latest Triassic of Poland

It is generally accepted that during the Triassic the composi− tion of tetrapod faunas underwent a series of fundamental transformations, mainly as a result of diversification of archosaurs and decline of therapsids (Benton 1994, 2004, 2006). The last herbivorous basal synapsids, dicynodonts, disappeared from the record in the early Norian of the Americas, about 220 Ma (Langer et al. 2007), being un− known from the Late Triassic of Europe. Here, we report a partially articulated skeleton and isolated bones of a giant rhino−size dicynodont in the Upper Triassic fluvial sedi− ments at Lisowice (Lipie Śląskie clay−pit) in southern Po− land. Paleobotanical data indicate an early Rhaetian age for the fauna (Dzik et al. 2008; Niedźwiedzki and Sulej 2008). The dicynodont bones are associated with bones of carnivo− rous dinosaurs, pterosaurs, as well as capitosaur and plagio− saur amphibians. Dicynodonts were represented in the Ger− manic Basin throughout the Late Triassic, as proven by findings of smaller dicynodonts in older deposits in the same area, associated there with temnospondyl amphibians. It ap− pears, thus, that the fossil record of tetrapod succession in the Late Triassic was strongly controlled by ecological fac− tors and biased by uneven representation of particular envi− ronments. The Lisowice assemblage proves that faunas dominated by dicynodonts did not entirely disappear at least until the end of the Triassic.

A NEW RAUISUCHIAN REPTILE (DIAPSIDA: ARCHOSAURIA) FROM THE LATE TRIASSIC OF POLAND

Abstract A crushed rauisuchian skull and several vertebrae belonging to a single individual have been found in the Upper Triassic strata at Krasiejów, Poland, probably corresponding in age to the Lehrberg Beds (late Carnian) of Baden-Württemberg, Germany. A maxilla of Teratosaurus suevicus from the early Norian (Stubensandstein at Heslach) is similar to that of the Krasiejów specimen. The dorsal process of the maxilla is more oblique than in T. suevicus, the medial anterior foramen is set on the medial side, contrary to being exposed anteriorly in T. suevicus, and foramina for replacement teeth are not connected by a dental groove and are set in straight line. A new species of Teratosaurus is proposed to accommodate the Polish material, and a more complete diagnosis of the genus is presented.

The Taxonomy and Anatomy of Rauisuchian Archosaurs from the Late Triassic of Germany and Poland

The German Late Triassic archosaur Teratosaurus suevicus is a historically important taxon, being the first described rauisuchian. Unfortunately the holotype is a single element, a maxilla, which is poorly preserved and incomplete. We redescribe this maxilla and identify a single potential autapomorphy. The fragmentary type specimen complicates attempts to refer additional material to this taxon, and other unassociated archosaur and rauisuchian specimens from the Mittlerer Stubensandstein of Germany cannot be referred to T. suevicus with any degree of confidence. The stratigraphically older T. silesiacus, from the upper Carnian of Poland, is represented by a much more complete and better preserved specimen. Comparison of the maxillae of T. suevicus and T. silesiacus reveals that the two are distinct taxa, contra recent suggestions, but also that they do not share any synapomorphies or a unique combination of characters relative to Postosuchus kirkpatricki and other rauisuchians. Thus, the Polish material must be transferred to a new genus, Polonosuchus gen. nov. Both Polonosuchus and Teratosaurus are very similar to Postosuchus kirkpatricki, and the three taxa are likely closely related.

Aetosauria: a clade of armoured pseudosuchians from the Upper Triassic continental beds

Abstract Aetosauria is a clade of obligately quadrupedal, heavily armoured pseudosuchians known from Upper Triassic (late Carnian–Rhaetian) strata on every modern continent except Australia and Antarctica. As many as 22 genera and 26 species ranging from 1 to 6 m in length, and with a body mass ranging from less than 10 to more than 500 kg, are known. Aetosauroides scagliai was recently recovered as the most basal aetosaur, placed outside of Stagonolepididae (the last common ancestor of Desmatosuchus and Aetosaurus). Interrelationships among the basal aetosaurs are not well understood but two clades with relatively apomorphic armour – the spinose Desmatosuchinae and the generally wide-bodied Typothoracisinae – are consistently recognized. Paramedian and lateral osteoderms are often distinctive at the generic level but variation within the carapace is not well understood in many taxa, warranting caution in assigning isolated osteoderms to specific taxa. The aetosaur skull and dentition varies across taxa, and there is increasing evidence that at least some aetosaurs relied on invertebrates and/or small vertebrates as a food source. Histological evidence indicates that, after an initial period of rapid growth, lines of arrested growth (LAGs) are common and later growth was relatively slow. The common and widespread Late Triassic ichnogenus Brachychirotherium probably represents the track of an aetosaur.

A new Late Triassic vertebrate fauna from Poland with turtles, aetosaurs, and coelophysoid dinosaurs

ABSTRACT We report a new site with an occurrence of isolated bones of a Palaeochersis-like turtle in Norian-Rhaetian fluvial sediments from southern Poland. The turtle remains are associated with bones of a medium-sized aetosaur, a coelophysoid dinosaur, and a larger carnivorous archosaur, as well as a hybodontid shark, ganoid and dipnoan fishes, and a large temnospondyl.

A Large Predatory Archosaur from the Late Triassic of Poland

We describe a new large predatory archosaur, Smok wawelski gen. et sp. nov., from the latest Triassic (latest Norian—early Rhaetian; approximately 205–200 Ma) of Lisowice (Lipie Śląskie clay-pit) in southern Poland. The length of the reconstructed skeleton is 5–6 m and that of the skull 50–60 cm, making S. wawelski larger than any other known predatory archosaur from the Late Triassic and Early Jurassic of central Europe (including theropod dinosaurs and “rauisuchian” crurotarsans). The holotype braincase is associated with skull, pelvic and isolated limb-bones found in close proximity (within 30 m), and we regard them as belonging to the same individual. Large, apparently tridactyl tracks that occur in the same rock unit may have been left by animals of the same species. The highly autapomorphic braincase shows large attachment areas for hypertrophied protractor pterygoideus muscles on the lateral surface and a wide, funnel-like region between the basal tubera and basipterygoid processes on the ventral surface. The skeleton (cranial and postcranial) possesses some features similar to those in theropod dinosaurs and others to those in large crocodile-line archosaurs (“rauisuchians”), rendering phylogenetic placement of S. wawelski difficult at this time.

Upper Permian Vertebrate Coprolites from Vyazniki and Gorokhovets, Vyatkian Regional Stage, Russian Platform

Abstract Numerous coprolites have been found in the Vyazniki and Gorokhovets localities of European Russia. Five identified coprolite-bearing horizons occur in the upper Permian deposits of the Vyatkian Regional Stage. Coprolites were collected from mudstone with a coprolite breccia-like layer and also from intraformational conglomerates that were deposited in a floodplain and overbank environment. Two coprolite morphotypes (A and B) are recognized from size and shape analysis of 32 specimens. Morphotype A has long, nonsegmented feces. Smaller, cylindrical or tubular-shaped coprolites of morphotype B are commonly segmented. SEM images of the coprolite matrix show spheres and thin-walled vesicles with diameters 0.5–4 µm. Electron Micro Probe (EMP) analyses of polished thin sections show microcrystalline carbonate-fluoride-bearing calcium phosphate with small amounts of calcium replaced in the crystal lattice. Optical microscopy and EMP investigations show that iron and manganese oxides are responsible for elevated iron and manganese concentrations in the bulk mass of coprolites. Other metals (V, Ni) can be associated with oxides forming spheroids with diameters 3–10 µm. REEs (rare earth elements, U, and other trace element concentrations suggest significant eolian sediment input to the burial environment of the coprolites. The scats contain fish scales and bones of tetrapods (amphibians or reptiles). In one large-sized coprolite, a small fragment of therapsid bone was also found. Both morphotypes are matched to carnivorous taxa within the Archosaurus rossicus zone of the Eastern Europe. The size and shape of the best-preserved specimens suggest that they were possibly produced by a large therapsid, anthracosaur, or early archosauromorph predator.

Vertebrate burrow system from the Upper Triassic of Poland

Abstract In this paper we report on a rare fossil vertebrate burrow system in Upper Triassic (Norian) fluvial deposits of the Holy Cross Mountains in central Poland. The burrows are preserved mainly by prominent green infillings in red mudstone and claystone exposed in the wall of a clay pit. The mode of occurrence, morphology, and size of the burrows suggests that cynodont therapsids most likely constructed them.

Mammal-like tooth from the Upper Triassic of Poland

Recent Triassic discoveries have extended the record of near-mammals (Mammaliaformes) back to the Norian, about 215 Ma, and reveal a significant diversity of Late Triassic (Norian-Rhaetian) forms. We now add to this Late Triassic diversity a nearly complete double-rooted right lower molariform tooth (ZPAL V.33/734) from the Polish Upper Triassic that is significant because it comes from uppermost Norian—lower Rhaetian rocks and is the first discovery of a mammal-like tooth in the Mesozoic of Poland. The described tooth shows transitional dental morphology between advanced cynodonts and mammaliaforms and it appears to represent a basal mammaliaform (genus Hallautherium), probably belonging to Morganucodonta.

First record of Mesozoic terrestrial vertebrates from Lithuania : phytosaurs (Diapsida: Archosauriformes) of probable Late Triassic age, with a review of phytosaur biogeography

Fossils of Mesozoic terrestrial vertebrates from Lithuania and the wider East Baltic region of Europe have previously been unknown. We here report the first Mesozoic terrestrial vertebrate fossils from Lithuania: two premaxillary specimens and three teeth that belong to Phytosauria, a common clade of semiaquatic Triassic archosauriforms. These specimens represent an uncrested phytosaur, similar to several species within the genera Paleorhinus , Parasuchus , Rutiodon and Nicrosaurus . Because phytosaurs are currently only known from the Upper Triassic, their discovery in northwestern Lithuania (the Saltiskiai clay-pit) suggests that at least part of the Triassic succession in this region is Late Triassic in age, and is not solely Early Triassic as has been previously considered. The new specimens are among the most northerly occurrences of phytosaurs in the Late Triassic, as Lithuania was approximately 7–10° further north than classic phytosaur-bearing localities in nearby Germany and Poland, and as much as 40° further north than the best-sampled phytosaur localities in North America. The far northerly occurrence of the Lithuanian fossils prompts a review of phytosaur biogeography and distribution, which suggests that these predators were widely distributed in the Triassic monsoonal belt but rarer in more arid regions.