Name: Maiacetus
(Good mother whale).
Phonetic: Migh-ah-see-tus.
Named By: P. D. Gingerich, M. al-Haq, W.
Koenigswald, W. J. Sanders, B. H. Smith & I.
S. Zalmut - 2009.
Classification: Chordata, Mammalia, Cetacea,
Archaeoceti, Protocetidae.
Species: M. inuus (type).
Diet: Carnivore/Piscivore.
Size: About 2.6 meters long.
Known locations: Pakistan - Habib Rahi Formation.
Time period: Lutetian of the Eocene.
Fossil representation: Skulls and partial post
cranial remains, possibly of male and female individuals.
The
name Maiacetus means ‘good mother whale’ and
this is a reference to
the fact that the holotype of Maiacetus was
composed of a skull with
post cranial skeletal remains, and inside of the post cranial
skeleton there appears to be the remains of a fossilised foetus. If
this interpretation is correct then this would mark the first discovery
of a foetus within an archeocetid whale.
An alternative theory
(Thewissen & McLellan, 2009) however has proposed that
the ‘foetus’ may have actually been eaten by the individual
Maiacetus in question. Counter to this however is
the noted lack of
feeding damage to the foetus skeleton, specifically a lack of tooth
marks on the bones.
A
second skull added to Maiacetus shows an individual
with a larger
skull, and this has been interpreted as belonging to a male
Maiacetus. If this is correct, then Maiacetus
will not just be the
first potential example of an archaeocetid foetus, but also one of
the earliest examples of sexual dimorphism within primitive whales.
Care should be taken not to confuse Maiacetus with the very similarly named Maiasaura, a hadrosaurid dinosaur from the late Cretaceous of North America.
Further reading
- New protocetid whale from the middle Eocene of Pakistan:
birth on land, precocial development, and sexual dimorphism. -
PLoS ONE 4 (2). - P. D. Gingerich, M. al-Haq, W.
Koenigswald, W. J. Sanders, B. H. Smith & I.
S.
Zalmut - 2009.
- Maiacetus: displaced fetus or last meal? -
PLoS ONE- J.
G. M. Thewissen & W. A. McLellan - 2009.