The world-renowned Posidonia Shale fossil beds in Germany have yielded another incredible discovery – a new species of ancient marine reptile that has been hiding in plain sight for nearly 47 years. Paleontologists have identified a previously unknown type of plesiosauroid, which they’ve named Plesionectes longicollum (“long-necked near-swimmer”). This remarkable find expands our understanding of prehistoric ocean ecosystems that existed during the Jurassic period, around 183 million years ago.

The specimen, a nearly complete skeleton with remnants of fossilized soft tissue, was originally excavated from a quarry in Holzmaden, Southwest Germany, in 1978. However, its unique anatomical features were only fully recognized through comprehensive scientific analysis, led by Sven Sachs of the Naturkunde-Museum Bielefeld.

“The specimen has been in collections for decades, but previous studies never fully explored its distinctive anatomy,” said Dr. Sachs. “Our detailed examination revealed an unusual combination of skeletal features that clearly distinguish it from all previously known plesiosaurs.”

This research, published by Dr. Sachs and co-author Dr. Daniel Madzia from the Polish Academy of Sciences, demonstrates that the Posidonia Shale contained even greater marine reptile diversity than previously recognized. The Plesionectes specimen is particularly significant as it represents the oldest known plesiosaur from the Holzmaden area.

“This discovery adds another piece to the puzzle of marine ecosystem evolution during a critical time in Earth’s history,” explained Dr. Madzia. “The early Toarcian period when this animal lived was marked by significant environmental changes, including a major oceanic anoxic event that affected marine life worldwide.”

The fossil is permanently housed at the Staatliches Museum für Naturkunde Stuttgart (Stuttgart State Museum of Natural History), where it is cataloged as specimen SMNS 51945. The Posidonia Shale has previously yielded five other plesiosaur species, further cementing its status as one of the world’s most important windows into Jurassic marine life.

The coelacanth, also known as the “living fossil,” has been a subject of fascination for scientists due to its unique anatomy that has remained largely unchanged since the extinction of the dinosaurs. A recent study published in Science Advances has revealed new insights into vertebrate evolution, shedding light on the cranial musculature of the African coelacanth (Latimeria chalumnae).

The researchers from the University of São Paulo (USP) and the Smithsonian Institution in the United States conducted a thorough examination of the fish’s anatomy, focusing on its cranial muscles. They discovered that only 13% of the previously identified evolutionary muscle novelties for the largest vertebrate lineages were accurate.

“Ultimately, it’s even more similar to cartilaginous fish and tetrapods than previously thought,” said Aléssio Datovo, a professor at the Museum of Zoology (MZ) at USP, who led the study. The researchers also identified nine new evolutionary transformations related to innovations in feeding and respiration in these groups.

Among the evolutionary novelties erroneously identified as present in coelacanths were muscles responsible for actively expanding the buccopharyngeal cavity, which extends from the mouth to the pharynx. However, the study showed that these supposed muscles in coelacanths were actually ligaments, which are structures incapable of contraction.

This discovery has significant implications for our understanding of vertebrate evolution, particularly regarding the cranial muscles of other large vertebrates. The researchers used three-dimensional microtomography images of the skulls of other fish groups to infer where the muscles found in coelacanths would fit, elucidating the evolution of these muscles in the first jawed vertebrates.

This study has shed new light on the evolution of vertebrate cranial musculature and highlights the importance of further research into this area. The discovery also underscores the significance of the coelacanth as a “living fossil,” providing valuable insights into the evolution of vertebrates that are not available from fossil records alone.

The study’s findings have far-reaching implications for our understanding of vertebrate evolution, and researchers intend to analyze similarities with the muscles of tetrapods, such as amphibians and reptiles, in future work.

Unveiling the Dinosaur’s Menu: A Fossilized Time Capsule Reveals the Sauropod’s Diet 100 Million Years Ago

A groundbreaking study published in the Cell Press journal Current Biology has shed light on the diet of one of the most fascinating creatures to have ever walked the Earth – the sauropod dinosaur. The research, led by Stephen Poropat of Curtin University, reveals that these gentle giants were herbivores and had a unique digestive system that relied heavily on gut microbes for digestion.

The study’s findings are based on an extraordinary discovery made in 2017 at the Australian Age of Dinosaurs Museum of Natural History. During an excavation of a sauropod skeleton from the mid-Cretaceous period, researchers stumbled upon a well-preserved cololite – a fossilized rock layer containing the dinosaur’s gut contents.

The analysis of the plant fossils within the cololite has confirmed several long-standing hypotheses about the sauropod diet. The research team found that these dinosaurs likely engaged in minimal oral processing of their food and instead relied on fermentation and their gut microbiota for digestion.

The variety of plants present in the cololite suggests that sauropods were indiscriminate bulk feeders, eating a range of foliage from conifers to leaves from flowering plants. This is supported by the presence of chemical biomarkers from both angiosperms and gymnosperms, indicating that at least some sauropods were not selective feeders.

The researchers’ findings have significant implications for our understanding of these massive herbivores and their role in ancient ecosystems. The study suggests that sauropods had successfully adapted to eat flowering plants within 40 million years of the first evidence of their presence in the fossil record.

In addition, the research team found evidence of small shoots, bracts, and seed pods in the cololite, implying that subadult Diamantinasaurus targeted new growth portions of conifers and seed ferns. This strategy of indiscriminate bulk feeding seems to have served sauropods well for 130 million years and might have enabled their success and longevity as a clade.

While this research has shed new light on the diet of sauropod dinosaurs, there are still limitations to consider. The study’s primary limitation is that the sauropod gut contents described constitute a single data point, which may not be representative of typical or adult sauropods’ diets.

This research was supported by funding from the Australian Research Council and has significant implications for our understanding of these fascinating creatures and their role in ancient ecosystems.