News

 

2024.09.30. PUBLICATION — Gu, L.A., Wolniewicz, A.S. and Liu, J., 2024. New information on the dentition of Chaohusaurus zhangjiawanensis (Reptilia, Ichthyosauriformes) from the Early Triassic of Yuan’an, Hubei Province, China. Swiss Journal of Palaeontology, 143(1), 1-16. doi: https://doi.org/10.1186/s13358-024-00331-8.

      

A new specimen of the early ichthyosaur Chaohusaurus zhangjiawanensis from the Early Triassic of Hubei Province, China, confirms heterodonty in this species. Like other species of Chaohusaurus, Ch. zjangjiawanensis had conical teeth in the front of the snout, and rounded teeth in the back of the jaws. However, the dentition of Ch. zhangjiawanensis was more robust than that of other members of the genus, indicating Ch. zhangjiawanensis had a diet richer in hard-shelled prey.

2024.09.30. PUBLICATION — Laboury, A., Stubbs, T.L., Wolniewicz, A.S., Liu, J., Scheyer, T.M., Jones, M.E. and Fischer, V., 2024. Contrasting macroevolutionary patterns in pelagic tetrapods across the Triassic–Jurassic transition. Evolution, qpae138. doi: https://doi.org/10.1093/evolut/qpae138.

      

A comprehensive study by an international team of researchers found that the evolutionary trajectories of Triassic–Jurassic ichthyosaurs and eosauropterygians – two groups of Mesozoic pelagic predators – differed markedly. Furthermore, the study provides evidence that the turnover of Mesozoic marine reptiles at the Triassic–Jurassic boundary was more gradual than previously believed, rather than catastrophic. However, one group of ichthyosaurs—the colossal shastasaurids—appears to have been severely affected by the Triassic–Jurassic extinctions.

2024.09.30. PUBLICATION — Bindellini, G., Wolniewicz, A.S., Miedema, F., Dal Sasso, C. and Scheyer, T.M., 2024. Postcranial anatomy of Besanosaurus leptorhynchus (Reptilia: Ichthyosauria) from the Middle Triassic Besano Formation of Monte San Giorgio (Italy/Switzerland), with implications for reconstructing the swimming styles of Triassic ichthyosaurs. Swiss Journal of Palaeontology, 143(1), 1-32. doi: https://doi.org/10.1186/s13358-024-00330-9.

      

Besanosaurus leptorhynchus is a large-bodied ichthyosaur from the Middle Triassic of Monte San Giorgio (Alps near the Italy–Switzerland border). In a new study, an international team of researchers describes its postcranial anatomy, revealing a combination of both ancestral and advanced ichthyosaur features. The swimming style of Besanosaurus is inferred to be somewhat intermediate between that of more basal and more derived ichthyosaurs.

 

 

2024.09.20. PUBLICATION — Świło M., Majewski W., Totten R.L., Lehrmann A.A., Anderson J.B. 2024. Multi-proxy record of Late Holocene climate events and westerly winds in Maxwell Bay, South Shetland Islands, Antarctica. Palaeogeography, Palaeoclimatology, Palaeoecology 654: 112450.
https://doi.org/10.1016/j.palaeo.2024.112450.

      

Climate change in Antarctica is neither geographically uniform nor synchronous. This paper presents new data from Maxwell Bay, a wide-open bay in the South Shetland Islands. Combined with other records from the area, we found a prominent expression of the Medieval Climate Anomaly and the Little Ice Age, associated with strong variability in westerly winds, which affect the presence of sea ice and the inflow of open ocean water. Studies like this help us to understand how climate is controlled in still understudied polar areas.

2024.09.18. PUBLICATION — P. Gorzelak, J. Stolarski, P. Bącal, P. Dubois, D. Kołbuk. 2024. Calcium-rich seawater affects the mechanical properties of echinoderm skeleton. Communications Earth & Environment 5, 467 . https://doi.org/10.1038/s43247-024-01609-y

      

Experiments on Recent sea urchins grown in seawater with a low Mg/Ca ratio have shown that they produce skeletons with lower magnesium content and nanohardness. These results may suggest that at certain times in the geological past (during the so-called calcite seas with a low Mg/Ca molar ratio) sea urchins were more susceptible to damage by abiotic processes and/or predation.

2024.09.18. PUBLICATION — Machalski, M., Duda, P. The influence of burrow-generated pseudobreccia on the preservation of fossil concentrations. Scientific Reports 14, 18893 (2024). https://doi.org/10.1038/s41598-024-69846-x

^{Figure: Visualization of the strongly burrowed junction between the Cretaceous (Maastrichtian) and Paleogene (Danian) deposits, based on computed tomography; illustrated slab comes from an outcrop at Bochotnica near Kazimierz Dolny, Poland.}

      

Discontinuity surfaces associated with fossil concentrations mark breaks in the marine sedimentary record. The transformation of such a surface into a "pseudobreccia" by burrowing invertebrates makes its interpretation difficult. We analyzed a strongly bioturbated interval on the Cretaceous–Paleogene boundary near Kazimierz Dolny in Poland, using i.a. three-dimensional X-ray computed tomography imaging. This allowed us to reinterpret this controversial section and propose guidelines for studies of similar intervals elsewhere.

 

2024.08.21. PUBLICATION — Stolarski, J., Coronado, I., Potocka, M., Janiszewska, K., Mazur, M., Baronnet, A., Cruz, J.A., Grauby, O., Meibom, A. 2024. Post-mortem recrystallization of biogenic amorphous calcium carbonate guided by the inherited macromolecular framework. Scientific Reports 14:17304, doi: 10.1038/s41598-024-68037-y

^{Figure: The mature gastrolith of the American lobster is originally composed of dozens of columnar units of amorphous calcium carbonate with a layered, nanogranular structure (left panel). One of the diagenetically altered (calcite) columnar units exhibits a complex, hierarchical structure with a braid-like microstructure and granular nanostructure (right panel).}

      

Biogenic minerals (biominerals) differ in structure and biogeochemical composition from their abiotic counterparts. Until now, it was believed that diagenetic changes in biominerals lead to the loss of most features indicative of their biogenic nature. In the published paper, we demonstrate that in the American lobster structures formed by amorphous calcium carbonate can crystallize post-mortem into calcite. The crystallization process is influenced by the inherited organic matrix, resulting in secondary calcite that meets some structural criteria for biominerals. Our observations help distinguishing biogenic carbonates.

2024.08.20. PUBLICATION — Salamon, Mariusz A.; Benyoucef, Madani; Jain, Sreepat; Benzaggagh, Mohamed; Płachno, Bartosz J.; Abdelhamid, Marouf A. M.; Ahmad, Fayez; Azar, Dany; Bouchemla, Imad; Brachaniec, Tomasz; El Ouali, Mohamed; El Qot, Gamal; Ferré, Bruno; Gorzelak, Przemysław; Krajewski, Marcin; Klompmaker, Adiël A.; Mekki, Fayçal; Paszcza, Karolina; Poatskievick-Pierezan, Bruna; Slami, Rafika; Hoşgör, İzzet. 2024. Jurassic and Cretaceous crinoids (Crinoidea, Echinodermata) from the southern Tethys margin (northern and eastern Africa, and southern Asia). Palaeontographica Abteilung A, 328 (1-6): 1-99. doi: 10.1127/pala/2024/0148

      

The first monographic study of several dozen crinoid taxa (including one new species) from the Jurassic and Cretaceous sediments of Africa and Asia (southern Tethys). Significant differences in the number of crinoid genera between the northern and southern parts of Tethys have been demonstrated. This is most likely a secondary effect caused by much better sampling and a long history of studies of crinoids from the northern Tethys.

 

      

Faunas from Eocene deep-sea methane-seep deposits from the flysch in Buje (Croatia) are described. They are composed chiefly of chemosymbiotic lucinid and thyasirid bivalves, families known already from the Cretaceous. Methane-seep deposits from Buje formed at conditions favourable also for vesicomyid and bathymodiolins known from some Eocene to Recent seeps, but these are lacking at Buje. However, both families occur in a few equivalent-aged seeps in the Pacific. We hypothesize that this is due to evolutionary antiquity of the deep-sea methane-seep faunas in the Tethys Ocean at that time.

      

We are glad to invite you to participate in 95th PalGes in Warsaw 2024 - Joint Meeting of the Polish Paleobiologists and the annual meeting of the Paläontologische Gesellschaft (Palges) on September 16 to 21, 2024 at the Faculty of Biology, University of Warsaw. The theme of this year's conference is "More than extinct species: the importance of fossil organisms for today's ecology, evolution and biodiversity conservation efforts across borders?" The official language of the meeting is English, however, associated outreach events are planned in German, English, and Polish. Within the organizers are: the Faculty of Biology University of Warsaw, the Faculty of Geology University of Warsaw, the Institute of Paleobiology Polish Academy of Sciences, the Palaeontological Section of the Polish Geological Society, the Polish Geological Institute – National Research Institute, and the Paläontologische Gesellschaft (PalGes).
For more information see: link .

^{Figure: illustration by Agnieszka Kapuscinska.}

      

An international team analysed functional morphology of the neck and paleoecology of the Late Cretaceous eutherian mammal Zalambdalestes lechei from Mongolia. An almost complete associated cervical skeleton, including six out of total seven vertebrae was found nearly 60 years ago by the Polish-Mongolian Paleontological Expedition in the Djadokhta Formation. Novel tools including micro-CT tomography now allow for linking the strange morphology to this animal’s feeding and defensive behaviour akin to modern tenrecs.

^{Figure: photo author: Ye-wei Fang, reconstruction author: Nikolay Zverkov.}

      

Mixosaurs were a group of ichthyosaurs from the Middle Triassic. They were characterized by a streamlined body and teeth used for crushing shells of marine invertebrates. Mixosaurs were abundant in the shallow waters of the Tethys and are known from hundreds of specimens, but their species diversity is poorly known. A new paper describes a new species of mixosaur from Yunnan Province in southwestern China – Mixosaurus luxiensis. The discovery allows us to better understand the anatomical and ecological diversity of mixosaurs from China and their relationships with species from Europe.

24^th June 2024 (Monday), 11:00 a.m., Dr Rafał Piechowski will give a seminar: "Rekonstrukcja umięśnienia na przykładzie żółwi.".

^{Figure: Maximum likelihood phylogeny based on the nuclear data set (upper box) indicating position of the new family Stephanocyathidae in comparison to Caryophyllidae sensu stricto. Lower box: skeletons of selected representatives of Stephanocyathidae in distal and lateral views.}

      

The paper documents another stage in elucidating the phylogenetic relationships among traditionally understood Caryophylliidae, considered until recently as the most species-rich group of predominantly deep-water scleractinian corals. Nuclear and mitochondrial DNA analyses revealed that the genera Stephanocyathus and Vaughanella exhibit their own gene transposition and lack a unique gene rearrangement that is a synapomorphy of the group containing the type genus Caryophyllia. Molecular characteristics and macromorphological features allow to segregate the genera Stephanocyathus, Vaughanella, and likely Ericiocyathus into a new family, Stephanocyathidae.

^{Figure: the studied specimen – photograph (left) and 3D model (middle) – and a phylogenetic tree of amniotes considered in the paper indicating the probable position of Saurodesmus robertsoni (right).}

      

184 years ago, a small bone was discovered in the Triassic of Scotland. Even though over the decades it was examined by some of the most significant paleontologists of their time, named Saurodesmus robertsoni, and variably interpreted as a femur of a turtle, humerus of a crocodile, or a bone of an animal resembling pareiasaurs or cynognathians, its systematic identity was never really established. To finally solve this mystery, the anatomy of amniote stylopodial bones is reviewed. The specimen is reassessed as a femur of a derived (probably tritylodontid) cynodont.

 

^{Figure: fossilized remains of Pliocene pathogenic bacteria (D–F) were found in a caries-affected tooth (A–C) of an extinct rodent.}

 

^{Figure: anatomy and evolutionary changes of the turtle humerus.}

      

Turtles are characterized by an unusual anatomy of the locomotor apparatus linked with the development of their shell incorporating modified elements of the axial skeleton and pectoral girdle. However, the appendicular skeleton was never properly documented in representatives of most turtle groups, and the anatomical terminology used by various authors was often ambiguous. The aim of this work is to present the anatomy of the humeri of many extant and extinct turtle species, to standardize the nomenclature, and to highlight phylogenetically meaningful characters.

 

13^th May 2024 (Monday), 11:00 a.m., prof. Wojciech Majewski will give a seminar: "Reakcja za zmiany środowiska i post-industrialna odbudowa populacji otwornic z fiordów Georgii Południowej, sub-Antarktyka".

^{Figure:Evolutionary succession of scaphitid ammonites against the upper Campanian and Maastrichtian stratigraphy with geographical and stratigraphical position of the Nahoryany site. M – macroconchs (females?), m – microconchs (males?)}

      

The lower Maastrichtian (Upper Cretaceous) shallow-marine deposits exposed at Nahoryany, south of Lviv (western Ukraine), have been known as a rich source of fossils since 1843. Today, the quarries do not exist but the fossils may be studied based on museum collections. The paper deals with scaphitid ammonites from Nahoryany on the basis of specimens housed in Lviv and Vienna palaeontological collections. The evolution, possible sexual dimorphism, and life habits of these common Late Cretaceous cephalopods have been discussed.

24^th April 2024 r (Wednesday), 11:00 a.m., Dr Tetsuto Miyashita will give a seminar: "Jawless Wonders and the Changing Views on the Origin of Vertebrates".

 

22^nd April 2024 r (Monday), 11:00 a.m., prof. Federico Fanti will give a seminar: "In the footsteps of giants: geo-paleontological discoveries in the Gobi desert of Mongolia".

^{Figure: location of the Chełm site, an example of a micromorphic brachiopod shell (Terebratulina longicollis), and the chalk succession with ranges of identified taxa.}

      

Shells of small (micromorphic) brachiopods are not so attractive as other fossils preserved in the white chalk facies, for instance the belemnite rostra or echinoid tests. Despite this, they are important for the Late Cretaceous stratigraphy and palaeoecology. We describe brachiopods from the Maastrichtian chalk at Chełm, eastern Poland. The studied assemblage is dominated by small forms and allows for precise dating of the succession and determination of its depositional environment.

^{Figure: A. Life reconstruction of the machimosaurid from south-central Poland by Stanisław Kugler. Typical specimen (whole body) and MZ VIII Vr-72 (head reconstruction). B. Overview of MZ VIII Vr-72 fossil specimen. C. A photograph of F2 (central part of preserved rostrum fragment). D. Close up of the teeth structure, with prominent enamel ornamentation.}

      

In the Jurassic period, besides the well-known plesiosaurs and ichthyosaurs, there existed a third group of widely distributed large predatory marine reptiles – the Thalattosuchia, popularly known as "sea crocodiles". A rostrum of a large teleosauroid from the Oxfordian of Załęcze Wielkie was studied. Mechanical preparation and application of computer microtomography allowed to interpret this fossil as a machimosaurid similar to genera Neosteneosaurus and Proexochokefalos. A pathological bending of the upper jaw of this individual occurred most likely during its lifetime.

15^th April 2024 r (Monday), 11:00 a.m., dr Łukasz Czepiński, dr hab. Tomasz Sulej i dr Tomasz Szczygielski will give a seminar:"Zmierzch ery gadów ssakokształtnych - raport z grantu".

^{Figure: Reconstruction of sea surface temperature (SST) based on multi-proxy analysis of elements in the skeletons of reef corals Porites and Diploastrea (upper panel), and differences in ratios between major microstructural skeletal components (Rapid Accretion Deposits vs. Thickening Deposits) in Porites and Diploastrea (lower panel).}

The published study offers a comprehensive analysis of geochemical proxies extracted from reef coral skeletons (Porites and Diploastrea) aimed to reconstruct sea surface temperature (SST). Employing a multi-element approach (e.g., Sr/Ca and Li/Mg) notably reduced uncertainties in temperature calibration. Discrepancies in SST reconstructions were more pronounced in Porites compared to Diploastrea colonies, attributed to variations in ratios between major microstructural skeletal components. These ratios influence the integration of trace elements and reflect physiological differences between taxa.

^{Figure: Vertebrate remains from the Triassic of Stryczowice: A, Maxilla of a procolophon; B, Reconstruction of trematosaur parasphenoid; C. Trematosaur parasphenoid in the sediment.}

      

Vertebrate bones are rare in the Lower Triassic deposits of the Holy Cross Mountains. We describe remains of Early Triassic amphibians (trematosaurs) and reptiles (a procolophon, a herbivorous reptile similar to lizards) from Stryczowice near Ostrowiec Świętokrzyski. Similar animals are known from the Triassic of Germany and Russia. Only fragmentary finds of trematosaurs are known from Poland, but there is a rich procolophon assemblage from Czatkowice (a suburb of Krzeszowice near Cracow). None of the Czatkowice procolophons matches that from Stryczowice, and there are no trematosaurs at Czatkowice. This may result from environmental differences between these sites.

 

 

 

11^th March 2024 (Monday), 11:00 a.m., dr Milan Chroust will give a seminar: "Fossil Turtles: Yesterday, Today and Tomorrow".

      

An article on palaeobionics ("Soft robotics informs how an early echinoderm moved") co-authored by Przemysław Gorzelak, PhD, was among 10 highlighted articles published in PNAS by the journal's editorial board in 2023 that have had a major impact on public understanding of science and research. (Selected highlights of 2023)
Congratulations!

^{Figure: Above the originally described skeleton of Bagaraatan, below the recent reconstruction.}

      

Bagaraatan ostromi is an enigmatic carnivorous dinosaur described from the Upper Cretaceous Nemegt Formation in Mongolia. For more than 30 years its systematic position remained unresolved. The revision of Bagaraatan revealed that this genus is a chimaera – its skeleton was initially reconstructed based on mixed bones of two different dinosaurs: an oviraptorosaur (cf. Elmisaurus) and a very young tyrannosaurid. It is still an open question whether Bagaraatan is in fact a separate representative of tyrannosaurids or a juvenile Tarbosaurus or Alioramus. Bagaraatan is among the smallest juvenile tyrannosaurids.

26^th February 2024 (Monday), 11:00 a.m., dr Łukasz Czepiński will give a seminar: "Deinonychozaury z późnej kredy Pustyni Gobi".

      

Many organisms exhibit astonishing biomineralization abilities, forming polymorphic minerals from the same chemical substance. Fish inner ear otoliths consist of calcium carbonate (CaCO₃) in various polymorphic forms (e.g., vaterite, aragonite). Proteins are known to be involved in controlling polymorphic forms, with a new study suggesting a mechanism involving phosphorylation of a protein responsible of biomineralisation. Phosphorylation corresponds to calcium carbonate crystallizing as vaterite, whereas its absence leads to calcite precipitation.

^{Figure: Corallum of solitary Ceratotrochus (Edwardsotrochus) duodecimcostatus from the upper Pliocene of Tunisia (distal and lateral views); longitudinal thin-section and virtual (mCT) longitudinal section of the coral skeleton with probably in-vivo polycha ete borings (ichnogenus Maeandropolydora).}

      

One of the basic taphonomic questions is whether the borings in skeletal structures were produced in vivo or post mortem. Borings influencing the growth of the skeleton were produced during the life of the animal; the same for borings that are distributed very close to the surface of the skeletal structure and are elsewhere known from deep penetration into the substrate. Conversely, borings that penetrate deeply into the skeletal structure and those that are always close to the surface, irrespective of the substrate, can be regarded as produced post mortem. These criteria are used to distinguish the two categories of polychaete, bryozoan, and phoronid borings made in coralla of fossil (Pliocene of Tunisia) solitary scleractinian coral Ceratotrochus.