Thursday, February 18, 2010

Large, Fossil Snake from Madagascar

Thomas C. Laduke and colleagues (2010) report on three species of Madagascar snakes that belong to the extinct families Madtsoiidae and Nigerophiidae. The assemblage lived in a highly season environment, with a semi-arid climate 65.5 to 70.6 million years ago.

The collection contained at least 16 different specimens of Madtsoia madagascariensis Hoffstetter, 1961. Laduke and co-workers have interpreted the fossils of this snake to be a heavy bodied, terrestrial generalist that probably resembled many of the modern day boas and pythons. Using the vertebrae to estimate the size of their largest specimen, they calculated a length of 5.1 meters, and a body diameter that was about 15 cm. Hoffstetter had previously reported a vertebrae of this species that was 50% than the one described in this study, and that bone predicts a length of about 8 meters. Associated with the snake fossils were the remains of Simosuchus clarki (a crocodyliform) and two small theropod dinosaurs which may have been in the diet of this snake. Madtsoiids are not known to have venom or specialized teeth for delivering venom, and Laduke and co-workers propose that it probably killed prey using constriction as opposed to just biting or pinioning prey.

In the same paper they also describe a new species of unusual madtsoid, Menarana nosymena, a snake estimated to be be about 2.4 meters in total length and apparently specialized for burrowing. They also describe Kelyiophis hechti, a nigerophiid.

The Citation for this article:
Laduke, T. C., D. W. Krause, J. D. Scanlon, and N. J. Kley. 2010. A Late Cretaceous (Maastrichtian) Snake assemblage from the Maevarano Formation, Mahajanga Basin, Madagascar. Journal of Vertebrate Paleontology 30:109-138.


  1. The number of fossil snakes that reach or exceed the 6.1 meters required for giant status is growing. While this article does not report a new giant snake it confirms the presence of large snakes in Madagascar. Today the largest snakes on Madagascar are the two species of Acrantophis which may exceed 3 meters.

  2. I wonder where that figure of "6.1 meters required for giant status" comes from. Of course 'giant' is a relative term, but I tend to think that any constrictor over 4 m is seriously big (more than one person can safely handle), and will be feeding on most available mammals except for the larger ungulates and primates. Here in Australia we don't have native ungulates or primates, but a number of fossil snakes as well as the largest extant pythons seem to max out between 5 and 6.5 m, and I'm happy to call those 'giants'. Then I suppose we need a new category of 'supergiants' for anything from about 8 m on up (of which we only know of one in Australia, a Pliocene python)...

  3. When Bob Henderson and I wrote Tales of Giant Snakes 6.1 meters seemed to be a natural breaking point for large snakes. 6.1 meters is 20 feet and it was a nice round number. Also, at that time we thought there were only 4 living snake species that exceed that size. Previously Clifford Pope (The Giant Snakes, 1961)had recognized six species at giants (Eunectes murinus, Boa constrictor, Broghammerus reticulatus, Python molurus, P. sebae, and Liasis amethystinus). The record sized boa turned out to be an anaconda and the record sized amethystinus specimens (now kinghorni)appeared to have some problems. But, kinghorni may yet prove to exceed the 6.1 meters.