Posted by: Loren Coleman on December 29th, 2009
The announcement of an intriguing new species of Sirenia (i.e., manatees, dugongs, sea cows) was noted in the December 12, 2009, issue of the Journal of Vertebrate Paleontology. It is an extinct pygmy sea cow (Eotheroides lambondrano) ~ illustrated above with skull inset ~ from the island of Madagascar. It, thus, would have been a small relative of the Bering Sea’s Steller’s Sea Cow (Hydrodamalis gigas) ~ shown below.
Steller’s Sea Cow, of course, is also considered extinct, but still modern sightings are recorded for that species. Could the Madagascan pygmy sirenian explain reports of cryptids (e.g. merbeings) seen in recent times near Madagascar?
Rachel Kaufman of the National Geographic News summarized the new finding, which is given here, in part:
A new species of extinct pygmy sea cow is one of the first fossil mammal species found in Madagascar from the mysterious time period between 80 million years ago and 90,000 years ago, experts say.
Known from a roughly 40-million-year-old skull and a few ribs, the new species has been named Eotheroides lambondrano, after the Malagasy word for dugong, which translates to “water bushpig.” At about seven feet (two meters) long, the ancient pygmy sea cow was smaller than the modern dugong, which ranges from about 8 to 10 feet (2.4 to 3 meters) in length….E. lambondrano is also unique in that its closest relatives would have lived in what is now India and Egypt, according to the study—making its Madagascan location all the more special….”Madagascar already has a lot of strange beasts, and we now have a glimpse of this species from so far away.”
The discovery of a valid species of pygmy sea cow calls for a review of the latest on the Amazonian Dwarf Manatee debate. In regard to this alleged new species, Wikipedia has a good, new (December 23, 2009) overview of what has occurred since the announced “discovery” of this new species, written possibly by an unknown British or Canadian author (RN1970?), (given in plain text below to retain the italicized names, which are critical to the passage):
The Dwarf Manatee (Trichechus “pygmaeus”, or mistakenly Trichechus “bernhardi”) is a possible species of manatee that lives in the freshwater habitats of the Amazon, though restricted to one tributary of the Aripuanã River. According to Marc van Roosmalen, the scientist who proposes it as a new species, it lives in shallow, fast running water and feeds on different species of aquatic plants than the Amazonian Manatee, which prefers deeper slower moving waters and the plants found there. Based on its tiny range, it has been suggested that the Dwarf Manatee is critically endangered, but at present it is not recognized by the IUCN.
Dwarf Manatees are typically about 130 cm long, and weigh about 60 kg, making them the smallest extant sirenians. It is overall very dark, almost black, with a white patch on the abdomen. It has been suggested that it actually represents an immature Amazonian Manatee, but they are reported to differ in proportions and colour. They are, however, at least very closely related, as mtDNA has failed to reveal any difference between the two. Based on mutation rates in manatees – if the Dwarf Manatee is distinct – this suggests a divergence time of less than 485,000 years. Daryl Domning, a Smithsonian Institution research associate and the world’s foremost experts on manatee evolution, has stated that the DNA evidence actually proves that these merely are immature Amazonian Manatees.
Disregarding its questionable validity as a species, the proposed name “Trichechus pygmaeus” is problematic. A formal description using that name was submitted to Nature, but it was rejected and consequently the article has only been published online. This has resulted in the invalidation of the name following chapter 3, article 8 of the ICZN code. [End Wikipedia; see here for references.]