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Why the strange nose? The peculiar case of Metarhinus and Sphenocoelus
Brontotheres (also known as titanotheres; Family BRONTOTHERIIDAE) are a family of extinct relatives of the horse and rhinoceros that lived approximately 35-55 million years ago in what is now North America and Asia. They lived during a period of time known as the Eocene Epoch (56 to 33.9 million years ago). Many had peculiar, forked-horns. Some grew to the size of small elephants. The low-crowned teeth of members of the family suggest that they were obligatory browsers (leaf-eaters). They inhabited forested regions, although the very large forms of later times (Chadronian, the latest age in the Eocene Epoch) would probably have inhabited more open meadow-like ground.
Two genera Metarhinus and Sphenocoelus (also known as Dolichorhinus) are particularly interesting. Members of the two genera were relatively small compared to most brontotheres and had little or no horn development. Species of Metarhinus were about the size of a tapir and while species of Sphenocoelus were a little larger. However, it is their usual nasal anatomy which radically changed the way they breathed that is completely unique and found in no other creatures known to science.
Bryozoans Described for the First Time from the Tamiami Formation (USA)
Jaleigh Pier
Bryozoans are tiny colonial animals that have a mineralized skeleton which typically encrusts onto hard surfaces in aquatic environments including rocks and shells. Dr. Emanuela Di Martino is a bryozoan specialist and describes them best:
“Bryozoans are small, aquatic, colony-forming invertebrate animals often mistaken for corals or seaweed. Each colony is comprised of genetically identical modular units called zooids. While zooids are microscopic, bryozoan colonies can range in size from a few millimetres to more than a metre wide.”
Like the cells of living sponges, bryozoan zooids have diverse forms and functions. There are specialized zooids for feeding, being either male or female for reproduction, and even those specific for defense called avicularia. Their physical appearance depends on their specific function within the colony. The great majority of bryozoans secrete calcareous skeletons, creating a lengthy fossil record dating back to the early Ordovician, about 475 million years ago.
Eternal Loving Embrace of Two Eocene Moths
For the average person, insects trapped in amber may spark images from the film Jurassic Park, where mosquitos were the key to resurrecting living dinosaurs. Although collecting dino DNA from fossil insects may not be feasible, there is still much to learn from these specimens frozen in time.
Dr. Thilo C. Fischer and Dr. Marie K. Hörnig are passionate palaeoentomologists (the study of fossil insects) and are beyond excited to share their fascinating discovery with the world! Not only did they find two individual moths (Order: Lepidoptera) trapped together in Baltic amber dating back 56-33 million years ago (Eocene), but they were a mating pair in copula! This is an extremely rare finding for any insect group and a first for the group Lepidoptera.
New Species of Fish from the Genus Eosemionotus
Although some fossil fish can be found in great abundance within mass mortality layers, others like the Middle Triassic genus Eosemionotus are extremely rare. For more than 80 years, Eosemionotus was known only through a single species discovered in Germany. It wasn’t until 2004 that a second species was officially published and now fifteen years after that we finally can include several new species into this once lonely genus. Dr. Adriana López-Arbarello and her team have identified three brand new species (E. diskosomus, E. sceltrichensis, and E. minutus) and have also further solidified the differences between the now five species based on their morphological variability.
Eosemionotus diskosomus. Complete specimens. 1, holotype MCSN 8082 (45 mm SL); 2, MCSN 8006 (60.5 mm SL); 3, PIMUZ T 2924 (22.5 mm SL); 4, MCSN 5617 (46.7 mm SL). Scale bars equal 5 mm.
Gerrhonotines, commonly known as alligator lizards, are a group of anguid lizards with a substantial fossil record as well as a diverse assemblage of species living today in North and Central America. This group of lizards has been well studied by biologists researching the molecular evolutionary history of the clade by using DNA from extant alligator lizards, but there has been a lack of reliable fossil data to take into account.
Elgaria multicarinata, photo by Scarpetta
From approximately 62 to 10 million years ago, meat-eating mammals called Hyainailouroids roamed Africa as one of the top predators. Hyainailouroids are part of a larger group of meat-eating mammals called hyaenodonts (sorry everyone, they're NOT related to hyenas) that were found in North America, Eurasia, and Africa between 62 and 9 million years ago. Recently PE authors Matthew R. Borths and Nancy J. Stevens examined the deciduous dentition (baby teeth) of this diverse group using CT imagery. PE appreciates Borths & Stevens for taking the time to answer a couple questions about their research for the PE blog.
Here’s what the authors had to say about their recent PE publication:
Lycopsids are one of the oldest groups of vascular plants. These ancient plants only have a few living relatives still around today, the clubmosses and quillworts. Lycopsids were some of the first plants to diversify on land and their long history stretches all the back to the late Silurian period, about 425 million years ago.
Shining clubmoss, Huperzia lucidula; Wikimedia Commons
Recently, authors Evreïnoff, Meyer-Berthaud, Decombeix, Lebrun, Steemans, and Tafforeau published an article in Palaeo Electronica about a new Late Devonian lycopsid from New South Wales, Australia. When asked about their most recent project, the authors wrote, “when studying how early land plants acquired the features that made them comparable to modern plants, Australia comes to a special place with the discovery of large leafy stems of the lycopsid Baragwanathia as early as the Late Silurian.”
“When we started [Palaeo Electronica] it was like a dare. Jump off that roof top, climb that tree, make an online journal.” – Jennifer Rumford
2017 marks the 20th anniversary of Palaeontologia Electronica (PE). For paleontologists, 20 years may not seem that long. But for the online, open-access journal PE, this represents a milestone that deserves celebration. The recently published commentary piece by Louys et al. offers a brief history of Palaeontological Electronica on the PE homepage . PE started in the early days of the internet in 1996; in fact it was one of the first peer-reviewed online academic journals in the world.
Fig 12. Elymys ? emryi new species from TBM, macrophotographs with corresponding line drawings of specimens
Earliest Uintan Mammals of the Bridger Basin
The Bridger Basin in southwestern Wyoming is paleontology heaven for Eocene mammal nerds like the author of this blog post. The middle Eocene Bridger Formation has yielded some of the most significant mammal fossils found in North America, including the primates Omomys carteri and Hemiacodon engardae. Distinct Bridger Formation mammals also include the strange multi-horned herbivore Uintatherium, the small weasel-shaped condylarth Hyopsodus, the giant brontotheres, carnivorous creodonts, and the blunt-toothed Stylinodon.
The fossil remains of marine mollusks have played a pivotal role in the understanding of stratigraphy around the world. Recently, Palaeontologia Electronica (PE) authors Lloyd Glawe, John Anderson, and Dennis Bell published an article about their study of microscopic mollusk shells from a set of nearly continuous cores from the Paleogene of Louisiana.