Day 143#: Moeritherium lyonsi
Today's animal of the day is Moeritherium lyonsi!
This species of proboscidean (which is the group that includes modern elephants and their ancient relatives) lived in northern and western Africa during the Eocene epoch. Moeritherium was first discovered in Egypt and was formally described by British paleontologist Charles William Andrews in 1901. He named the genus after the ancient Lake Moeris, a former oasis located in the same region where Moeritherium was unearthed. This lake has since mostly dried up, and the only remnant of it is a hypersaline lake known as Lake Qarun. Andrews originally believed that Moeritherium was an early ancestor of the mastodons, but the exact placement of where Moeritherium fits on the proboscidean family tree is unclear.
Image credit: Luci Betti-Nash
For a while, some paleontologists even thought it may have been a common ancestor between proboscideans and sirenia, the family that includes manatees and dugongs. However, this theory has since been disproven. Most paleontologists consider Moeritherium to be an early proboscidean that existed before the split between the two main groups of proboscideans: the elephantiforms (which include mammoths, mastodons, and modern elephants) and the deinotheres (which include Deinotherium and several other types of extinct proboscideans).
Image credit: Hemiauchenia
Moeritherium lyonsi isn't the only species of Moeritherium discovered, with there currently being four other species in the genus, but it was the first one to be discovered, and so it is considered the type species. Unlike the later species of giant proboscideans, Moeritherium was quite small (about 7.5 ft long and 2.3 ft tall at the shoulder) and had more of a tapir-like prehensile snout instead of a long trunk like elephants do. It had several adaptations that seem to suggest it would have been semi-aquatic, including ears that were higher up on the skull so they were less likely to get water inside of them, broad torsos to assist with diving, and relatively short legs compared to other similarly sized proboscideans. It probably could have even used its snout as a snorkel, like how modern-day elephants and tapirs do.
Image credit: Joschua Knüppe
The environment that Moeritherium lyonsi would have lived in was a tropical lowland plain with various ponds and slow-moving streams scattered about. The presence of mudstone found in the area also suggests that swamps likely could have formed alongside the rivers and streams. Now extinct species of ospreys, flamingos, herons, storks, shoebills, cormorants, and jacanas would have lived alongside Moeritherium in these tropical wetlands, along with predatory snakehead fish that searched for prey in the reeds. Eventually, this lush environment would be replaced by open woodlands and steppes, causing Moeritherium to go extinct.
