New vertebrate assemblage from marginal-marine and land Lower Keuper strata (Ladinian, Middle Triassic) of Miedary, Silesia, SW Poland

Vertebrate remains, mostly nothosaurid vertebrae and long bones, archosaur partially preserved long bones and teeth (probably rauisuchid remains), fish teeth and scales, are described from the Lower Keuper Miedary Beds (Ladinian, Middle Triassic) of Miedary, Silesia, SW Poland. The analyzed vertebrate fossils were collected from three lithologically different types of deposits. The first assemblage, which contains nothosaurid and fish remains, occurs in yellowish dolomites, where poorly preseved invertebrate macrofossils were also found (marine bivalves and brachiopods). In grey yellowish, sometimes greenish or red clays, rare isolated bones and teeth of large archosaur were found. In sandstone intercalations partially preserved and highly disarticulated fish fossils were identified. In all assemblages osteological remains are generally very well preserved. This new interesting vertebrate bones association from the upper part of the Middle Triassic marginal-marine strata of Poland has been correlated with age equivalents from other regions of Europe

Possible hominin footprints from the late Miocene (c. 5.7 Ma) of Crete?

© 2017 The Geologists' Association. We describe late Miocene tetrapod footprints (tracks) from the Trachilos locality in western Crete (Greece), which show hominin-like characteristics. They occur in an emergent horizon within an otherwise marginal marine succession of Messinian age (latest Miocene), dated to approximately 5.7 Ma (million years), just prior to the Messinian Salinity Crisis. The tracks indicate that the trackmaker lacked claws, and was bipedal, plantigrade, pentadactyl and strongly entaxonic. The impression of the large and non-divergent first digit (hallux) has a narrow neck and bulbous asymmetrical distal pad. The lateral digit impressions become progressively smaller so that the digital region as a whole is strongly asymmetrical. A large, rounded ball impression is associated with the hallux. Morphometric analysis shows the footprints to have outlines that are distinct from modern non-hominin primates and resemble those of hominins. The interpretation of these footprints is potentially controversial. The print morphology suggests that the trackmaker was a basal member of the clade Hominini, but as Crete is some distance outside the known geographical range of pre-Pleistocene hominins we must also entertain the possibility that they represent a hitherto unknown late Miocene primate that convergently evolved human-like foot anatomy

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

An elephant-sized Late Triassic synapsid with erect limbs

Tomasz Sulej, Grzegorz Niedźwiedzki (2018): An elephant-sized Late Triassic synapsid with erect limbs. Science 363 (6422): 78-80, DOI: 10.1126/science.aal485

Borkowice – a world-class paleontological site with footprints and bones of Early Jurassic dinosaurs

As part of the implementation of the Polish Geological Survey numerous and perfectly preserved dinosaur footprints were discovered in the upper Hettangian (Lower Jurassic) barrier-lagoon deposits, outcropping in the ceramic clay pit in Borkowice (Przysucha County, Poland). A large part of the specimens shows (especially visible in 3D scans) three-dimensional natural casts of dinosaur feet, on which anatomical features and impressions of the scaly skin are preserved in unusual details. These are the best-preserved traces of dinosaurs so far discovered in Poland and the quality of their preservation is equal to the best-known discoveries worldwide. In order for such a state of preservation to be possible, a very special sequence of sedimentary/taphonomic events had to take place in a very short time. The collection also includes records of ethology (behaviour) left by dinosaurs running, swimming, resting and sitting on a muddy sediment, as well as many enigmatic biogenic structures, probably related to various life activities of dinosaurs living there. So far, several hundred dinosaur tracks, representing at least seven different species of these animals have been collected and secured in Borkowice, and the prospects for new finds are much more promising. Unique bone remains of ornithischian dinosaurs preserved in the form of casts have also been found. It is necessary to act in cooperation with local authorities and the entrepreneur exploiting the clay deposits in order to secure and protect the geoheritage site

Fig. 2 in An elephant-sized Late Triassic synapsid with erect limbs

Fig. 2. Comparison of the reconstructed pectoral girdle of Lisowicia bojani with another dicynodont, dinosaur, and recent mammal. (A) Position of bones of L. bojani in anterior and lateral views. Some proportions of the bones were estimated by means of comparison with articulated skeletons of Parakannemeyeria (IVPP V. 979) and Sinokannemeyeria (IVPP V.974), but most were inferred from the size of articulation areas. (B) Reconstruction of large dicynodont Stahleckeria (GPIT/RE/8001) in anterior and lateral views. (C and D) Hypothetical flexibility of the humerus in protraction-retraction. (E) Reconstruction of rhinoceros Diceros in anterior and lateral views based on MPUWr 502223. (F) Reconstruction of Triceratops in anterior and lateral views based on (27). Scale bars, 10 cm

Fig. 3 in An elephant-sized Late Triassic synapsid with erect limbs

Fig. 3. Phylogeny of kannemeyeriiform dicynodonts and its relationship with the changes in femur length of dicynodonts and sauropodomorphs. (A) Time-calibrated phylogeny of the Triassic dicynodonts simplified after (22) (numerical ages for the base and top of Norian are based on the Chronostratigraphic Chart of the ICS v. 2018/8) with position of L. bojani. (B) Femur length (body size proxy) of sauropodomorph (black squares) and dicynodont (gray circles) taxa from the Middle to Late Triassic plotted at the stratigraphic range midpoints for each taxon. (C) Comparison of dicynodont femur bones (1, 2, ZPAL V.33/763, Lisowicia; 3, UCMP 32394, Placerias; 4, MCZ 378 58M, Ischigualastia; 5, MCN PV 3600, Dinodontosaurus; 6, GPIT/ RE/8002, Stahleckeria)