Mammalodon

Mammalodon Temporal range: Late Oligocene PreЄ Є O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Cetacea
Suborder:	Mysticeti
Family:	Mammalodontidae
Genus:	Mammalodon
Binomial name
Mammalodon colliveri Pritchard, 1939

Mammalodon is an extinct genus of whale that was discovered in 1932. It is an early baleen whale which still had teeth, as opposed to baleen plates.^[1] It is one of two genera in the family Mammalodontidae.

Modern whales have numerous plates with frayed edges called whalebones (or baleen). The whale ingests a mouthful of water then filters prey (such as krill) through the baleen.

Description

Mammalodon, with a length of 2.5m, was smaller and more basal than modern baleen whales.^[2] It had a short face, a delicate Premaxilla with only one or two incisors and the lateral rim of the internal auditory meatus was lengthened towards the brain case which formed a longitudinal ridge. Unlike modern baleen whales, Mammalodon was endowed with well-developed teeth.

Palaeobiology

As with the closely related genus Janjucetus, Mammalodon lacked baleen, instead possessing well-developed teeth.^[1] As such, it was not able to filter-feed in the same manner as extant baleen whales, making its diet and ecological niche a mystery.^[1] As the teeth are widely spaced, it has been suggested that they may have developed a method of filter-feeding unlike that of other whales.^[3] It is hypothosised that it was a bottom filter feeder, its blunt snout helping to suck up organisms from the sea floor.^[4]

References

1. ^ ^{a b c} Fitzgerald EMG. 2006. A bizarre new toothed mysticete (Cetacea) from Australia and the early evolution of baleen whales. Proceedings of the Royal Society B 273: 2955-2963.
2. ^ http://blogs.discovermagazine.com/80beats/2009/12/28/early-mini-whale-slurped-up-mud-to-find-hidden-prey/
3. ^ Evolution of Aquatic Tetrapods
4. ^ Fitzgerald, E. M. G. (2010). "The morphology and systematics of Mammalodon colliveri (Cetacea: Mysticeti), a toothed mysticete from the Oligocene of Australia". Zoological Journal of the Linnean Society 158 (2): 367–476. doi:10.1111/j.1096-3642.2009.00572.x. 

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