Reclassification Determines a New Genus of Fossil Horseshoe Crab
Identifying taxa and how they are related to one another (a field known as systematics) can be challenging. This is especially true of fossils where preservation can be variable and evolutionary stories are long and complex. As a result, classification is consistently revisited and modified as new discoveries provide a larger overall picture of how living things are related to each other.
A recent taxonomic revision published in Palaeontologia electronica (PE) has reclassified a horseshoe crab specimen and instead identified it as a new genus and species. Originally part of the family Paleolimulidae, the new species Tasmaniolimulus patersoni has also been moved into a different family: Austrolimulidae.
Giraffids Presented at the First Palaeontological Virtual Congress
The widespread availability of technology is advancing not only research itself, but the ways through which research is communicated to a broader audience. In December 2018, the very first Palaeontological Virtual Congress (PVC) was held connecting the palaeontological community all over the world through the internet. Palaeontologia Electronica (PE) has the pleasure of publishing research presented at the PVC in a special issue you can access here.
Dr. Maria Rios is an author on the first paper published in this special issue and comments on her experience at the PVC.
Biostratigraphy for Invertebrate Fossils
Biostratigraphy is a tool in palaeontology where fossils are used to date rocks in a relative sense. Throughout Earth’s history, in times of bursting diversity, species in the fossil record can be used to tell the relative age of the surrounding rocks.
For example, let’s say you were in the field and discovered ‘Species Y’. You know ‘Species Y’ appeared in the rock record after ‘Species X’ but before ‘Species Z’, so you can determine a relative age for the rocks you are looking at. In many cases, the best fossils for biostratigraphy are those that are found in high abundances over a large geographic area that preserve very well and live for a short time interval before dying out.
A New Eocene Crab Species
A recent article published in Palaeontologia Electronica (PE) highlights a discovery of a new species of fossilized crab from the Middle Eocene (47-41 million years ago) of Spain. Kromtitis is a well-known genus of Eocene crab that has a rather ornate shell carapace with examples from Italy, Hungary, Austria, Denmark and even the Neogene of Jamaica. This finding however is the first for the Iberian Peninsula.
Ancient Trophic Interactions
Panama, the land bridge connecting the north and south American continents is known for its lush forests and tropical waters. This ideal central location between continents allowed two evolutionarily distinct wave populations of plants and animals to crash into each other creating a mixing pot of evolution. These novel interactions over the last ~10 million years has made Panama the lush green biodiversity hotspot we know today.
However, if we rewind to the Pliocene (5.3-2.58 million years ago) the land bridge was still developing. The region was sprinkled with islands separated by a warm shallow sea with a very thin isthmus, “ideal for marine megafauna, where whales, fishes, and abundant benthic invertebrates thrived” says Dirley Cortés.
Dirley Cortés is a researcher studying marine paleoecology of the Early Cretaceous, but also has fieldwork experience in the Panamanian region. It was these fieldwork connections that led to a recent discovery of whale remains which reveal interesting signs of shark predation.
A fossil beaked whale from Hokkaido, Japan
Beaked whales (Family: Ziphiidae) are part of an easily recognised family of toothed whales known for their elongated beaks. Fossil evidence for beaked whales dates back as far as the Miocene (15 million years ago). Despite a singficant increase in our knowledge of beaked whale evolution, the evolution of their ear bone (periotic) shape in particular is poorly understood. Among the fossil beaked whale, preserved ear bones are rare compared to skulls. However, recently, Yoshihiro Tanaka and his colleagues described a beaked whale fossil! The fossil, described from the Chepotsunai Formation of Hokkaido, Japan was designated TTM-1 includes preserved ear bones, isolated teeth and vertebrate.
The forelimbs of Dilophosaurus: What can they tell us about an iconic dinosaur?
Dilophosaurus wetherilli is an iconic carnivorous dinosaur. This bipedal theropod (characterized by hollow bones and birdlike hindlimbs) dinosaur from the Lower Jurassic Period (201.3 million years ago - 174.1 million years ago) is known for the thin-boned crests on its snout. Dilophosaurus, over 6 m long, is from the Kayenta Formation of Arizona. As with all extinct animals, in order to understand how Dilophosaurus wetherilli lived, palaeontologists must study the relationships between the structure and function of the animal. The study of this relationship is called “functional morphology”. Recently, a PE paper by Philip J. Senter and Corwin Sullivan provided some interesting insight into the behaviour of this dinosaur by studying the range of motion of Dilophosaurus’ forelimbs.
The Strange Teeth of the Carboniferous Shark Edestus
Sharks have been popularized in the media for decades, from the famous Jaws film of the 1970s, to more modern Megalodon movies, and even an annual dedicated Shark Week on the Discovery Channel. Humans have become wary of these creatures portrayed as man-eating machines and, honestly, giant jaws lined with rows upon rows of teeth do not sound like a particularly pleasant encounter.
Sharks are some of the oldest vertebrates on the planet, having existed more than 450 million years! Arguably some of the most intriguing examples of specialized shark evolution come from the late Paleozoic (358-251 million years ago).
When Slow Evolution is the Best Survival Tactic
Fossils often indicate what environmental conditions were like at different times in earth’s history. As climates change over time, so does life since certain characteristics are more beneficial in specific climates. For example, crocodile fossils from the Eocene of Antarctica indicate a warm temperate climate ~50 million years ago. Both physical characteristics and behavior make crocs much more suitable to a lush green Antarctica rather than the current frozen over tundra. But what about species able to withstand various climate shifts over several million years, yet physically remains mostly unchanged?
Unlocking the secrets of the thylacine: The skeletal atlas of an iconic marsupial
The thylacine (Thylacinus cynocephalus), sometimes referred to as a Tasmanian tiger (due to the striped pattern on its back) or the Tasmania wolf (due to the dog like appearance), is one of Australia’s most iconic extinct mammals. Thylacines are thought to have gone extinct in the wild by the 1930s, with the last surviving captive animal having died in 1936. This was due, to a mass-extermination of the thylacines across Tasmania. Sadly, despite their now iconic nature and more recent public interest, very few useful specimens exist in collections and a complete atlas of the skeleton of the Thylacine has never been published. This is where a recent PE paper by Natalie M. Warburton, Kenny J. Travouillon, and Aaron B. Camens comes into play.