FOSSIL PREPARATION: MAMMOTH TEETH

Mammoths of Wrangell Island

Mammoths were were herbivore grazers native to Africa, Europe, Asia and North America. They lived out their long lives, 60-80 years, on the mammoth steppe, a periglacial landscape with lush grass vegetation. Mammoths used their well-designed teeth to graze on grasses, leaves, trees, shrubs and moss. Theirs was not a pretty end. Mammoths from this isolated population on Wrangell Island lost the genetic lottery with DNA mutations so abundant that they eventually led to their extinction.

In a paper published in PLOS in 2017, Rebekah Rogers describes that last populations of these once mighty beasts:

"The last woolly mammoths to walk the Earth were so wracked with genetic disease that they lost their sense of smell, shunned company, and had a strange shiny coat."

These genetic mutations may have given the last woolly mammoths "silky, shiny satin fur and let do a loss of olfactory receptors, responsible for the sense of smell, as well as substances in urine involved in social status and attracting a mate." In any event, their end was not a pretty one or the graceful exit one might have imagined. Excess of genomic defects in a woolly mammoth on Wrangel island; Rebekah L. Rogers , Montgomery Slatkin; Published: March 2, 2017https://doi.org/10.1371/journal.pgen.1006601

EOCENE FOSSIL TURTLE

Baena arenosa / Green River Stone Company

An Eocene Cryptodiran Fossil Turtle, Baena arenosa, from fine-grained lime mud outcrops in the Green River Formation, Wyoming, USA.

This fellow, with the extra-long tail, marks the last of his lineage as the extinct family Baenidae appeared first in the Jurassic and died out at the end of the Eocene. We've found specimens of Baena, along with 14 other species of turtles in seven genera and five families in the Lower Eocene San Jose Formation, San Juan Basin of New Mexico.

This specimen is from the Green River Formation of Wyoming which was once the bottom of one of an extensive series of Eocene lakes. The Green River Formation is particularly abundant in beautifully preserved fossil fish, eleven species of reptiles including a 13.5ft crocodile, an armadillo-like mammal, Brachianodon westorum, bats, birds and other fresh-water aquatic goodies.

This specimen of a beautiful Baena was found and prepped by the Green River Stone Company. They purchased their private 12-acre quarry about 20 years ago. It's at the Eocene lake's centre, shared with Fossil Butte National Monument about 24 kilometres (15 miles) west of Kemmerer, Lincoln County, Wyoming.

FOSSIL SAND DOLLARS

Fossil Sand Dollars / Cassibuloid Ancestry

These lovelies are fossil sand dollars with their beautiful five-fold radial symmetry and petal-like pattern. They are echinoids, a group of lovely echinoderms with flattened, rigid, globular skeletons made of thin calcium carbonate plates. They look a bit like sea-biscuits and are sometimes referred to as such.

Their ancestors diverged from an irregular order of echinoids called cassibuloids during the Jurassic. The first true genus of sand dollar, Togocyamus, arose during the Paleocene. While millions of years old, they retain their recognizable form and look very similar to ones we might find living in our oceans and along burrowing on our beaches today.

BLUE MUSSELS

Blue Mussels / Mytilus edulis

Blue mussels live in intertidal areas and inlets attached to rocks and other hard substrates by strong, stretchy thread-like structures called byssal threads.

They are tasty, edible marine bivalves, molluscs, in the family Mytilidae and they've done well for themselves. Mussels have a range of over 4000 km in waters around the world.

Temperature, salinity and food supply are key factors in how mussels grow and have a huge impact on their shape. Environmental stressors cause curvatures to show up in mussel populations and can help us understand environmental changes happening in our local waters.