Fossil Find May Conclude Controversy Over Hippo Origins

Two pygmy hippos (Choeropsis liberiensis) photographed at the Columbus Zoo by yours truly. The evolutionary origin of such mammals
 has been long unknown, although a recent study in Nature Communications proposes an answer.

A new paper published in the journal Nature Communications has shed crucial light on the ancestry of Africa’s sub-Saharan semiaquatic giant, the hippopotamus. The origins of these animals have long been shrouded in ambiguity but, according to the recent study, can now be definitively placed with the fossil ungulate family Anthracotheriidae. First found in coal deposits, the anthracotheres were aquatic browsers dating back to the late Eocene in Asia and North America.¹ Anthracotheres were among the first animals to colonize Africa, although their range was quite diverse throughout the Oligocene and Miocene epochs.¹ Morphological features such as the flaring snout, wide heavy feet, hippo-like lower jaw, cetacean-like premolars, and prominent tusks of anthracotheres like Elomeryx and Merycopotamus have been cited in support of a link with Hippopotamidae and Whippomorpha (the clade uniting whales and hippos) as a whole.^1,2 The swamp-dwelling tendency of anthracotheres indicated by the presence of their fossil remains in remnant coal seams likely hints at what stimulated differences in morphology and specilization between the otherwise closely related whales and hippos. Stem-whales most probably evolved in coastal environments promoting a carnivorous diet whereas the anthracotherian hippo-progenitors inhabited habitats in which they were restricted to feeding on aquatic plants. As some extant ungulates like pigs occasionally exploit a carnivorous diet, it is not too difficult to imagine stem-whales adopting this trait under restrictive ecological pressures. While fossil stem-cetaceans are numerous and well documented, the ancestry of the 'river horse' has been quite the enigma with ghost lineages remaining between the known anthracothere lineages and the oldest fossil hippopotamus. However, the fossil material described in the Nature Communications publication may help to bridge this paleozoological gap.

New Fossils Reveal The Mother Continent for South American Monkeys

Illustration of Perupithecus ucayaliensis by Jorge González

Arguably one of the best nicknames for the continent Africa is that of 'The Mother Continent', a name owing to the fact that our own Mitochondrial Eve can be traced to this location. However, Homo sapiens was not the only primate species to derive out of Africa. A paper recently published in the journal Nature has revealed new fossil material which sheds light on the origins of South America’s iconic monkey species. In 2010, a team of paleontologists led by Los Angeles County Natural History Museum curator Dr. Ken Campbell uncovered the teeth of three novel extinct primates in the east Peruvian Amazon. The first specimen took two years to identify as a result of its anatomy being distinct from that of modern day South American monkeys, the platyrrhines. The date of this species was traced to the Eocene epoch approximately 36 million years ago, making it ten million years older than any other fossil platyrrhine known. As a result, the newly named Perupithecus ucayaliensis is considered by scientists as a significant piece of the puzzle that is the evolutionary history of South American monkeys.

A New Year and New Zoological Musings

The Etendeka round-eared sengi, a new species of elephant shrew which posed a surprise to mammalogists in 2014. (Source)

With the occurrence of this New Year's Day, yet another year of my writing on this blog has transpired. I hope to deliver fresh material throughout this coming year, with an increased focus on non-cryptozoological topics. I feel that time constraints and my own personal favoritism for the study of unverified animal species have caused me to neglect other zoological matters and even miss opportunities to write on recent discoveries. Also, I have since come to a significant turning point of sorts in regard to my views on this controversial field and its more popular mystery animal elements.