''Macrocranion'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

of extinct mammal from the

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

epoch of Europe and North America. Exceptional fossils have has been found in the

Messel Pit The Messel pit (german: Grube Messel) is a disused quarry near the village of Messel (Landkreis Darmstadt-Dieburg, Hesse) about southeast of Frankfurt am Main, Germany. Bituminous shale was mined there. Because of its abundance of well-preserve ...

of Germany. ''Macrocranion'' species are often described as forest-floor predators, about the size of small

squirrels Squirrels are members of the family Sciuridae, a family that includes small or medium-size rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrels. ...

but with longer limbs. The genus is represented at the Messel Pit site by two species, ''M. tupaidon'' and ''M. tenerum''. ''M. tupaiodon'' had woolly fur with no spikes. Although possibly an

omnivore An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nut ...

, fossil remains indicate the specimen had eaten

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% ...

near the time of its death. This small animal was approximately fifteen cm in length, with long back legs capable of considerable speed. The fossil of ''M. tenerum'' is five cm long. The species also had long legs for rapid movement, but its fur included a spiky protection. The long legs, however, indicate the animal couldn't have effectively rolled up for defense. Fossilized stomach remains show that ''M. tenerums diet included ants, so it may have been an

insectivore A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant that eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores wer ...

. The oldest species are ''M. vandebroeki'' from the Paleocene-Eocene transition of Northern Europe and ''M. junnei'' from the Wasatchian (

Early Eocene In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...

) of

Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the sou ...

References

Amphilemuridae Prehistoric Eulipotyphla Eocene mammals of Europe Eocene mammals of North America Prehistoric placental genera Fossils of Germany Fossil taxa described in 1949 {{paleo-eulipotyphla-stub