Thursday, March 5, 2015

Tapirs of the Gray Fossil Site...Wait, what's a tapir?

Four of the five living tapir species; Lowland Tapir (top left),
Baird's Tapir (top right), Mountain Tapir (bottom left), and
Asian Tapir (bottom right).
Tapirs are by far the most frequently encountered animal found at the Gray Fossil Site. They account for over 90% of the larger animal remains found with over 100 individuals of all ages. Gray is, in fact, the most prolific fossil tapir site in the world. Despite this claim to fame, a surprising number of those who visit our museum have never heard of a tapir. This post will therefore serve as an introduction to these fascinating animals.

The closest modern relatives to tapirs are horses and rhinos, all of which are part of a group of hoofed mammals called the odd-toed ungulates. The earliest tapirs are known to have lived during the early Eocene of North America, about 55 million years ago. These first tapirs were small animals, some no bigger than house cats. Later tapirs would grow to be many times larger. The five species alive today all range in mass from 200 to around 700 pounds (90 to 317kg).
Tapirs are part of a group of mammals called perissodactyls or odd-toed
ungulates. Rhinos and horses also fall within this grouping.
 Apart from size, tapirs have remained virtually unchanged over their long history. All species, both living and extinct, have muscular, compact bodies and toes ending in blunt hooves, four on the front feet and three on the rear feet. Tapirs also possess a short trunk or proboscis, similar to that of an elephant. This trunk is highly mobile and serves as a tool to gather and handle food. Tapir calves have a coat of short, brownish fur patterned with pale stripes and spots that camouflages them against the forest floor.

A baby Lowland Tapir.
Modern tapirs are found only in the tropical forests of South America and Southeast Asia. As recently as 13,000 years ago, however, these animals could be found all over the world as far as northern North America and Europe. Four of the five living tapirs prefer to live in warm, lowland forest environments. The Mountain Tapir is adapted to live in the cold highlands of the Andes Mountains.

All tapirs demonstrate a fondness for water and spend large parts of the day swimming or resting in rivers and lakes. They instinctively retreat into deeper waters when they sense danger. In their respective habitats, tapirs consume a wide variety of leaves and fruits. They are also very important for their ecosystems because they help disperse seeds, and many plants have come to depend on them.

References & Further Reading
Colbert MW (2005). “The facial skeleton of the early Oligocene Colodon (Perissodactyla, Tapiroidea)”. Paleontologica Electronica 8(12A) <Full Article>

Hulbert RC (2005). “Late Miocene Tapirus (Mammalia, Perissodactyla) from Florida, with description of a new species, Tapirus webbi”. Bulletin of the Florida Museum of Natural History 45: 465-494 <Full Article>

Hulbert RC, Wallace SC, Klippel WE, Parmalee PW (2009). “Cranial morphology and systematics of an extraordinary sample of the late Neogene Dwarf Tapir, Tapirus polkensis (Olsen)”. Journal of Paleontology 83(2): 238-262 <Abstract>

Janis C (1984). “Tapirs as living fossils”. pp 80-86 in N. Eldridge and S. M. Stanly (eds), Living Fossils. Springer Verlag, New York <Abstract>

Olsen SJ (1960). “Age and faunal relationships of Tapiravus remains from Florida”. Journal of Paleontology 34: 164-167 <Full Article>

Friday, January 23, 2015

All About Gray Fossil Site's Red Panda

Bristol’s Panda (Pristinailurus bristoli), found only at the Gray Fossil Site, is an ancient North American relative of the living Red Panda (Ailurus fulgens). Known from intact skeletons, it is the most complete fossil ailurid from North America and most complete ailurine found anywhere else in the world.

Its genus name (Pristinailurus) comes from the Latin word pristinus meaning “former” or “previous”, and Ailurus for the living Red Panda (Ailurus fulgens) to which the fossil species is closely related. The species name (bristoli) is named for Larry Bristol who discovered the first fossils from Bristol’s Panda. Commonly, this species is also known as “Bristol’s Appalachian Panda.” The word “panda” itself is derived from the Nepalese term nigalya poonya, which means “bamboo-eater,” a reference to the diets of the living Red Panda and the unrelated Panda Bear (Ailuropoda melanoleuca).

Habitat & Distribution
Bristol’s Panda is special because it is one of only two ailurine pandas known from North America. The other is an unnamed Parailurus species from Washington State, and it is known by a single tooth. Although the living distribution of Bristol’s Panda was undoubtedly more expansive, fossils are known only from the late Miocene-early Pliocene locality of Gray, Tennessee. The environment in which it lived was a forested region with a subtropical climate as evidenced by the alligator and other fossils unearthed here.

Physical Attributes                               
Bristol’s Panda differs from the Red Panda in a number of ways, the most obvious being its much larger size. The fossil panda would have weighed 8 to 15kg (17 to 33lbs) in life, compared to the modern Red Panda which averages 5kg (11lbs). The skull of Bristol’s Panda is not as domed and it lacks a sagittal crest suggesting a weaker bite. However, its snout was longer with larger incisors and canines. The upper carnassial is also longer and not as wide, suggesting that it was not as dependent on plant matter as part of its diet.

Bristol’s Panda shares several physical characteristics with the modern Red Panda which point to climbing ability. They both have a long tail for counterbalance, broad paws with recurved semi-retractable claws, and a nimble body with powerful muscles in the forelimbs and lower back. There are some major differences between the ancient and modern red pandas. Several aspects of Bristol’s Panda’s anatomy hint at a more terrestrial existence than its living relative. Compared to the tree-dwelling Red Panda, Bristol’s Panda has proportionally shorter and more robust forelimbs while the hind limbs were significantly longer. This body plan is typical of carnivorans such as civets, small cats, and certain foxes that actively hunt on the ground while retaining considerable climbing ability.
Skull and head comparison of Bristol's Panda (left) and Red Panda (right).
We see further evidence of a terrestrial lifestyle in Bristol’s Panda in the arrangement of its wrist and finger bones. The modern Red Panda has particularly well-developed “false thumbs” on its front paws that form an effective clamp for gripping tree trunks and thin branches. The false thumbs of Bristol’s Panda are proportionally much smaller. This suggests less frequent usage of the “false thumbs” and overall less time spent in the higher branches of trees.
Size comparison between the Bristol's Panda and the Red Panda. Note
the larger size and proportionally shorter forelimbs, longer hind limbs,
and longer body in the Bristol's Panda.
Ecology & Behavior
The body proportions of Bristol’s Panda were those of an active and agile predator that spent most of its time on the ground but could readily climb trees when necessary. Like many small forest-dwelling carnivorans it was probably nocturnal and solitary, perhaps sleeping in burrows during the day and emerging at night to forage. Together with the Woodland Badger (Arctomeles dimolodontus), Bristol’s Panda is the most commonly found small carnivoran found at the Gray Fossil Site. This suggests that these animals had a relatively high population density, which is typical of small mammals with versatile diets. For Bristol’s Panda, the menu would have included various small animals and fruits, as well as eggs and insects, all of which are typically abundant in forested habitats. With food sources available all year round, Bristol’s Panda may have required small territories.

References & Further Reading
Wallace SC (2011). “Advanced Members of the Ailuridae (Lesser or Red Pandas – Subfamily Ailurinae)”. pp 43-59 in AR Glatston (ed), Red Panda: Biology and Conservation of the First Panda <Book>

Salesa MJ, Anton M, Morales J (2005). “Evidence of a false thumb in a fossil carnivore clarifies the evolution of pandas”. PNAS 130(2): 379-382 <Full article>

Wallace SC, Wang X (2004). “Two new carnivores from an unusual late Tertiary forest biota in eastern North America”. Nature 431: 556-559 <Full article>

Roberts MS & Gittleman JL (1984). “Ailurus fulgens”. Mammalian Species 222: 1-8 <Full article>

Hello, fossil fans!

Hello, fossil fans!

Here at the ETSU Natural History Museum and Gray Fossil Site, we have decided to start a blog so we can tell you in more detail about what we're finding and how it's significant to the local community as well as the scientific community.

We would love for our blog to serve as a platform to promote more understanding about what we do as well as for a place for you to ask questions. Real paleontologists are involved in this project and will be answering all of your questions.

So, if you are a fossil/rock/mineral/artifact enthusiast or you are considering a career in paleontology/archaeology/geology, welcome! We hope you will find this page to be both entertaining and informative. If there is anything in particular that you would like to see on this page,. shoot us a message! We want this to be a page for you!

Check back with us every so often to see what we're up to. Our fist post is going to be about red pandas and what they are, what kind we find here in Gray, and why that's so awesome. We will also be sharing some really cool illustrations by one of our very own graduate students.