Brusatte S.L.,American Museum of Natural History |
Brusatte S.L.,Columbia University |
Butler R.J.,Ludwig Maximilians University of Munich |
Niedzwiedzki G.,Uppsala University |
And 5 more authors.
Geological Magazine | Year: 2013
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 Šaltiškiai 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. Copyright © 2012 Cambridge University Press.
Niedzwiedzki G.,Uppsala University |
Brusatte S.L.,University of Edinburgh |
Sulej T.,Institute of Paleobiology PAN |
Butler R.J.,University of Birmingham
Palaeontology | Year: 2014
The rise of dinosaurs during the Triassic is a widely studied evolutionary radiation, but there are still many unanswered questions about early dinosaur evolution and biogeography that are hampered by an unevenly sampled Late Triassic fossil record. Although very common in western North America and parts of South America, dinosaur (and more basal dinosauriform) remains are relatively rare in the Upper Triassic deposits of Europe, making any new discoveries critically important. One of the most diverse dinosauriform assemblages from Europe comes from the Poręba site in Poland, a recently described locality with exposures of the Zbąszynek Beds, which have a palynomorph assemblage characteristic for the mid-late Norian in the biostratigraphic schemes of the Germanic Basin. Using a synapomorphy-based approach, we evaluate several isolated dinosauriform specimens from Poręba. This assemblage includes a silesaurid, a herrerasaurid and remains of another type of theropod (potentially a neotheropod). The Poręba herrerasaurid is the first record of this rare group of primitive dinosaurs from Europe and one of the youngest records worldwide, whereas the silesaurid is the youngest record of a silesaurid from Europe. These findings indicate that silesaurids persisted alongside true dinosaurs into the mid-late Norian of Europe and that silesaurid-herrerasaurid-neotheropod assemblages (which are also known from the Norian of North America, at low latitudes) were more widespread geographically and latitudinally than previously thought. Silesaurid-herrerasaurid-neotheropod assemblages may have been a common ecological structuring of dinosaurs during their early evolution, and their widespread distribution may indicate weak palaeolatitudinal controls on early dinosaur biogeography during the latest Triassic. © The Palaeontological Association.
Melnikova G.K.,Institute of Geology |
Roniewicz E.,Institute of Paleobiology PAN
Geologica Belgica | Year: 2012
Four microstructural groups of corals representing the orders Scleractinia and Hexanthiniaria are known in the Triassic and in the Early Jurassic of the Tethys realm. In the south-eastern Pamir Mountains, Lower Jurassic corals occur from the Hettangian to Toarcian sediments. Hettangian?-Sinemurian and Sinemurian coral faunas discussed in this paper come from the Gurumdy and Mynkhajir facies zones. Coral associations are composed of classical Early Jurassic West European and North African (Moroccan) taxa, accompanied by several genera previously unknown in the West Tethys. After the end-Triassic extinction, the Early Jurassic recovery faunas of the Pamir Mountains contain Stylophyllopsis, Eocomoseris, a genus related to Elysastrea, and a large number of Jurassic genera: Oppelismilia, Archaeosmilia, Archaeosmiliopsis, Stylosmilia, Proaplophyllia, Cylismilia, Intersmilia, Prodonacosmilia, Pachysmilia, Placophyllia and Stephanastrea. More or less fragmented corals and complete skeletons are found in detrital carbonate, oolitic, or micritic limestone facies. Phaceloid growth forms prevail over solitary and massive ones.
Fostowicz-Frelik L.,Institute of Paleobiology PAN |
Sulej T.,Institute of Paleobiology PAN
Lethaia | Year: 2010
The phylogenetic relationships of Silesaurus opolensis have been the subject of intense debate since its discovery. Silesaurus possesses some features characteristic of ornithischian dinosaurs, such as the presence of a beak at the front of the lower jaw, yet it lacks a number of important femoral and dental synapomorphies of Dinosauria. The microstructure of the long bones (femur, tibia and metatarsal) and ribs of this species reveals a relatively intensive rate of growth, comparable with that seen in small dinosaurs and the gracile crocodylomorph Terrestrisuchus. Cortical bone formed mainly by periosteal tissue with fibro-lamellar matrix (in older specimens parallel fibred) shows very little secondary remodelling and only in one specimen (large tibia ZPAL Ab III/1885) few lines of arrested growth are present in the outermost cortex. The vascularization is relatively dense, mainly longitudinal and ceases towards the periphery, forming almost avascular parallel fibred bone at the bone surface. This indicates maturation and significant decrease in the growth ratio in mature specimens of S. opolensis. The delicate trabeculae exhibit cores formed by the primary cancellous tissue lined with lamellar endosteal bone. The rather intense growth of S. opolensis implies a relatively high metabolic rate. Moreover, evidence from the fibro-lamellar tissue, predominant in the cortex, suggests that this kind of rapid bone deposition could be more typical of Archosauria than previously assumed, a prerequisite for the evolution of the very fast growth rates observed in large ornithischians, sauropods and large theropods. □ Archosauria, Bone histology, Dinosauriformes, Late Triassic, Silesaurus opolensis. © 2009 The Authors, Journal compilation © 2009 The Lethaia Foundation.
Lukowiak M.,Institute of Paleobiology PAN
Helgoland Marine Research | Year: 2016
The method of spicular analysis that examines surficial sediments has been used to study the sponge spicule assemblage in the lagoon reef of Bocas del Toro, Panama. The method allowed to recognize some highly diagnostic spicule morphotypes that may belong to four sponge species as yet unnoticed in this area. The presence of these sponges must have been overlooked while studying faunistic compositions within an ecosystem due to their cryptic and/or excavating nature. Despite some limitations, the method of spicular analysis may be used as a supplementary tool for the studies of modern shallow-water sponge communities. © 2016 Łukowiak.