How do you tell Pleistocene mammoth, mastodon, & gomphothere molars apart? All three occur in Pleistocene deposits in South Carolina and throughout the southeastern USA but are frequently confused with one another. Here's a #fossilexplainer comic from Dr. Boessenecker to help!
Mammoth (Mammuthus) teeth are perhaps the easiest to distinguish as they have many plates of enamel that are flattened from front to back - typically 15-30 plates or so; these plates are thin, perhaps 1 cm thick, and the enamel itself is also thin - usually about 2-3 mm.
American mastodon (Mammut) teeth are much lower and have 3-5 transverse sharp ridge-like cusps that wear down into diamond-shaped wear facets. The enamel is quite thick (4-10 cm), & looks fibrous in structure when broken.
Cuvier's gomphothere (Cuvieronius) look very similar to mastodon teeth, and generally has cusps that are low & transverse but are rounded at their tips & possess many additional finger-like cusps and lobes. As a result, the wear facets are curved and 'squiggly'.
The enamel is also quite thick, 4-10 mm.
Smaller teeth from further forward in the jaws - premolars - generally can be identified using these features, but have fewer cusps/plates in all three elephants.
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Juvenile fossils can be challenging to identify and are frequently ignored - but our scientists relish such a challenge, and reported the first growth series ever for a toothed baleen whale! New specimens of Coronodon havensteini showcase skull changes through growth.
The two juvenile specimens shown here surprisingly have snouts and palates that are the same proportion as the adult - normally, the snout starts off shorter and lengthens during growth in cetaceans. This suggests that feeding behavior constrained its shape.
The earbones also become quite inflated during growth - the posterior process becomes longer and wider, and the body of the periotic and anterior process become markedly inflated! These might get recognized as different species if found isolated.
#Juneteenth
Sharing a post we made last June.
How might racial injustice have anything to do with something as seemingly innocuous as paleontology? The study of fossils from the Charleston area began within 50 years of its founding as a plantation economy-based British colony. 🧵
Shortly after plantations were constructed, enslaved Africans began finding unusual items in the earth.
The first correctly identified vertebrate fossils from North America were dug up on the "Stono Plantation".
The plantation owners thought the teeth belonged to a giant that perished in Noah's flood; English botanist Mark Catesby, who was visiting, interviewed many of the enslaved Africans who had seen the teeth, & identified them as elephant teeth - which are very similar to mammoth 🦷
What, if anything, does paleontology have to do with racial injustice? The 1st identified vertebrate fossils from North America, mammoth teeth - were identified as elephant teeth by enslaved Africans on the Stono Plantation in 1725. These fossils led to hypothesis of extinction.
Many other fossils were excavated by unnamed people, likely slaves, on plantations - like the original fossil of the archaeocete whale Dorudon serratus, found on the Mazyck Plantation in the 1840s.
Many early 19th century naturalists in Charleston were either slaveowners or benefited from vast fortunes of their slaveowning families - a privilege that afforded them the time to devote to scientific research, considered a leisurely activity for 'gentlemen' at the time.