paleololigo

Highs and Lows of the Rocky Mountains in the Middle to Late Eocene – #365papers – 2017 – 97

#365papers for April 7, 2017

Fan, Constensius, and Dettman, 2017, Prolonged high relief in the northern Cordilleran orogenic front during middle and late Eocene extension based on stable isotope paleoaltimetry: Earth and Plantery Science Letters, v. 457, p. 376-384.

What’s it about?

The Rocky Mountains have been around for a long, long time. This study focuses on a part of the Rockies that was still growing between about 46 to about 34 million years ago. Through the study of fossil soils and fossil snails, the authors show that the difference between the lowest basins and the highest mountain peaks was around 4 km – which is a lot!Continue reading “Highs and Lows of the Rocky Mountains in the Middle to Late Eocene – #365papers – 2017 – 97”

G is for Grangeria – #AtoZChallenge – 2017 – Uintan Mammals

G is for Grangeria.

Grangeria is a large hoofed mammal closely related to horses that lived during the middle Eocene. Whether or not Grangeria is a valid name, or that members of Grangeria are better called Eomoropus is a topic of discussion in paleontology.

Nevertheless, Grangeria is a member of a group called chalicotheres, which were unusual hoofed mammals in that their front legs were proportionately very long, and they may have knuckle-walked like modern anteaters.

F is for Forstercooperia – #AtoZChallenge – 2017 – Uintan Mammals

F is for Forstercooperia

Forstercooperia is a rhinocerotid (a hoofed mammal closely related to rhinos) from the Eocene of Asia. Originally, this name was applied to a similar mammal from the Uinta Formation of Utah, but the Utahn specimens have since been renamed Uintaceras (“Uinta horn”)

*Forstercooperia* by Roman Yevseyev (on DeviantArt)

E is for Epihippus – #AtoZChallenge – 2017 – Uintan Mammals

E is for Epihippus.

Epihippus is a fossil horse. You know it’s a horse because of the ‘hippus’ in its name, which means ‘horse.’

These horses were smaller than modern horses and possessed four hoofed toes on its front legs and three hoofed toes on its back legs.

*Epihippus gracilis*. Credit: U.S. National Park Service.

A Little Giant from John Day – #365papers – 2017 – 96

#365papers for April 6, 2017

Mihlbachler and Samuels, 2016, A small-bodied species of Brontotheriidae from the middle Eocene Nut Beds of the Clarno Formation, John Day Basin, Oregon: Journal of Paleontology, v. 90, p. 1233-1244.

What’s it about?

This is a description of a new species of brontothere, giant rhino-like mammals from the middle Eocene (about 44 million years ago). This new species, Xylotitan, is actually small, as brontotheres go – only about the size of a modern tapir.Continue reading “A Little Giant from John Day – #365papers – 2017 – 96”

How Aridity Drove Plants to Deal with Air in their ‘Veins’ – #365papers – 2017 – 95

#365papers for April 5, 2017

Larter, Pfautsch, Domec, Trueba, Nagalingum and Delzon, 2017, Aridity drove the evolution of extremem embolism resistance and the radiation of the conifer genus Callitris: New Phytologist, doi: 10.1111/nph.14545

What’s it about?

Callitris is a conifer (evergreen) that lives in Australia. Many members of this genus live in highly arid areas and have to cope with long dry spells. These dry spells can result in air being drawn into the xylem (water conducting channels) of the trees. Just like in humans, air bubbles in the xylem (or air in our blood vessels) can be fatal. In both cases, an air bubble is called an embolism

It turns out that there is a relationship between a tree’s ability to resist embolisms and the history of the tree’s ancestors. Trees whose ancestors grew in more arid environments have greater resistance to embolisms.Continue reading “How Aridity Drove Plants to Deal with Air in their ‘Veins’ – #365papers – 2017 – 95”

Tall Teeth and Grazing Diets – #365papers – 2017 – 94

#365papers for April 4, 2017

Feranec and Pagnac, 2017, Hypsodonty, horses, and the spread of C4 grasses during the middle Miocene in southern California: Evolutionary Ecology Research, v. 18, p. 201-223.

What’s it about?

Modern horses have very tall (hypsodont) teeth. This is thought to be an adaptation for grazing, because chewing grass wears down teeth faster than chewing the leaves off a tree.

A fossil horse tooth from Natural Trap Cave. The grinding surface is on the left. Only about 1/5 of this tooth stuck above the gum line.

Paleontologists use the height of the tooth (its hypsodonty) to distinguish animals that grazed from those that ate bushes, shrubs, and trees (called browsing).

Isotopically, grasses look different from leaves from bushes. This chemical difference gets recorded into teeth.

The authors use isotopes from early horses that are hypsodont to show that tall teeth are related to doing more grazing.Continue reading “Tall Teeth and Grazing Diets – #365papers – 2017 – 94”

D is for Diplobunops – #AtoZChallenge – 2017 – Uintan Mammals

D is for Diplobunops.

Diplobunops is a small hoofed mammal related to pigs. The group of mammals that contains Diplobunops and other related species is loosely referred to as oreodonts.

*Diplobunops matthewi* (Peterson, 1919) – fossil mammal skeleton from the Eocene of Utah, USA. (CM 11801, Carnegie Museum of Natural History, Pittsburgh, Pennsylvania, USA)

C is for Colodon – #AtoZChallenge – 2017 – Uintan Mammals

C is for Colodon.

The genus Colodon made its first appearance in the Uintan. It is a type of hooved mammal most closely related to modern tapirs.

You can read more about Colodon here:

Colbert, 2005, The Facial Skeleton of the Early Oligocene Colodon (Perissodactyla, Tapiroidea): Palaeontologia Electronica, v. 8.

Puppy Play Bows Don’t Always Mean the Same Thing – #365papers – 2017 – 93

#365papers for April 3, 2017

Byosiere, Espinosa, Marshall-Pescini, Smuts, and Range, 2016, Investigating the function of play bows in dog and wold puppies (Canis lupus familiaris, Canis lupus occidentalis): PLOS one, v. 11, e0168570.

What’s it about?

Dog owners are familiar with the friendly play bow of their dogs, with the front legs outstretched and the rump high in the air. Where pet dogs are concerned, this is usually associated with playing – the kind of playing that doesn’t look much like playing but more like two dogs are going to kill each other. Ok, well maybe just my dogs.

Wolves (adults and puppies) also use the play bow. The question posed by the authors is what purpose does the play bow serve.Continue reading “Puppy Play Bows Don’t Always Mean the Same Thing – #365papers – 2017 – 93”