Stereomicrograph of Tyrannobdella rex jaw showing large teeth on a single jaw. by Phillips, et al. 2010
The new T. rex has ferociously large teeth lining a single jaw — but its length is less than two inches long. Tyrannobdella rex, a new species and genus of leech, was discovered when doctors plucked it from the nose of a girl who’d recently been bathing in an Amazonian river. Described in PLoS ONE, the blood sucker had led to the revision of a group of leeches that has a habit of feeding from body orifices of mammals.
“Because of our analysis of morphology and DNA, we think that Tyrannobdella rex is most closely related to another leech that gets into the mouths of livestock in Mexico,” says Anna Phillips, a graduate student affiliated with the American Museum of Natural History and the first author of the paper. The related species Pintobdella chiapasensis hails from Chiapas and is typically hosted by tapir and cows. Analysis of genetic sequences places these species with others found in the world’s tropics, suggesting that their common ancestor must have lived when the continents were pressed together into a single land mass, or before Pangaea broke up.
“We named it Tyrannobdella rex because of its enormous teeth,” says Mark Siddall, curator in the Division of Invertebrate Zoology. “Besides, the earliest species in this family of these leeches no-doubt shared an environment with dinosaurs about 200 million years ago, when some ancestor of our T. rex may have been up that other T. rex’s nose.”
For more on Mark Siddall, watch a recent field video of the curator searching for leeches in Rwanda.
De-Leeching Ankles on a Desolate Coast with Mark Siddall, Curator of Invertebrate Zoology
This year, scientists at the American Museum of Natural History are celebrating the 200th anniversary of Charles Darwin’s birth and the 1859 publication of On the Origin of Species with a collection of vignettes describing expeditions and ideas with links to Darwin’s seminal work.
The Island of Chiloé may protect part of the Chilean coast from the winds of the Pacific Ocean, but it offers little refuge for the travelling naturalist.
When Charles Darwin rode with his team across the island on January 22, 1835 he recalled a beautiful day and “trees…in full flower [that] perfumed the air.” Yet even this lovely vista “could hardly dissipate the effects of the gloomy dampness of the forest. Moreover, the many dead trunks that stand like skeletons never fail to give to these primeval woods a character of solemnity.”
More than 160 years later, Mark Siddall and his graduate student Liz Borda made a similar excursion to what is now the Parque Nacional de Chiloé. As they tramped through dense stands of old-growth Nothofagus and Fitzroya trees in intense wind and
driving rain, they found they shared Darwin’s observation that if they “could forget the gloom and ceaseless rain of winter, Chiloé might pass for a charming island.”
The project that brought Siddall and Borda to Chile shared something else with Darwin, too. “Our purpose in Southern Chile was to rediscover two species of leeches, Americobdella valdiviana and Mesobdella gemmata, that I thought were critical to understanding the evolution of this group,” says Siddall. “Transitional forms—species that have characteristics of two distinct but evolutionarily related groups—are central to Darwin’s theories.”
In 1909 the American Museum of Natural History’s Herbert Lang and James Chapin embarked on a scientific expedition to the northeastern Belgian Congo. Their trip would ultimately last five and a half years yielding significant zoological and anthropological findings for the museum.
Exactly 100 years later another museum scientist, Dr. Mark Siddall, embarked on an expedition to the neighboring Rwanda. As a curator of invertebrate zoology he travelled to Rwanda in search of leeches — an animal that Lang and Chapin brought back amongst their original findings. Siddall’s research focuses on various aspects of leeches including the compound allowing them to stop blood from clotting and their DNA. In total he collected five distinct species of leeches on this latest trip.
Watch as Siddall traverses Rwanda’s rugged landscape and interacts with the local population in search of the curious blood sucking creatures.
