Mammalodon
Encyclopedia
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. 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.
than modern baleen whales. It had a short face, a delicate Premaxilla
with only one or two incisor
s and the lateral rim of the internal auditory meatus
was lengthened towards the brain case which formed a longitudinal ridge. Unlike modern baleen whale
s, Mammalodon was endowed with well-developed teeth.
, Mammalodon lacked baleen, instead possessing well-developed teeth. 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. 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. It is hypothosised that it was a bottom filter feeder, its blunt snout helping to suck up organisms from the sea floor.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of whale
Whale
Whale is the common name for various marine mammals of the order Cetacea. The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to suborder Odontoceti . This suborder also includes the sperm whale, killer whale, pilot whale, and beluga...
that was discovered in 1932. It is an early baleen whale which still had teeth, as opposed to baleen plates. It is one of two genera in the family Mammalodontidae
Mammalodontidae
Mammalodontidae is an extinct family of whales known from the Oligocene of Australia.There are currently two genera is this family: Janjucetus and Mammalodon. After a new cladistic analysis by Fitzgerald , Janjucetus was transferred into Mammalodontidae, thereby making Janjucetidae a junior synonym...
.
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
Krill
Krill is the common name given to the order Euphausiacea of shrimp-like marine crustaceans. Also known as euphausiids, these small invertebrates are found in all oceans of the world...
) through the baleen.
Description
Mammalodon, with a length of 2.5m, was smaller and more basalBasal (phylogenetics)
In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...
than modern baleen whales. It had a short face, a delicate Premaxilla
Premaxilla
The incisive bone is the portion of the maxilla adjacent to the incisors. It is a pair of small cranial bones at the very tip of the jaws of many animals, usually bearing teeth, but not always. They are connected to the maxilla and the nasals....
with only one or two incisor
Incisor
Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...
s and the lateral rim of the internal auditory meatus
Internal auditory meatus
The internal auditory meatus is a canal in the petrous part of the temporal bone of the skull that carries nerves from inside the cranium towards the middle and inner ear compartments namely cranial nerve VII and cranial nerve VIII.-Structure:The...
was lengthened towards the brain case which formed a longitudinal ridge. Unlike modern baleen whale
Whale
Whale is the common name for various marine mammals of the order Cetacea. The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to suborder Odontoceti . This suborder also includes the sperm whale, killer whale, pilot whale, and beluga...
s, Mammalodon was endowed with well-developed teeth.
Palaeobiology
As with the closely related genus JanjucetusJanjucetus
Janjucetus is an extinct genus of whale, and a basal form of the Mysticeti, a clade which includes the extant baleen whales. The only known species, Janjucetus hunderi, lived during the late Oligocene, about 25 million years ago in coastal seas off southeast Australia. Unlike modern mysticetes, it...
, Mammalodon lacked baleen, instead possessing well-developed teeth. 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. 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. It is hypothosised that it was a bottom filter feeder, its blunt snout helping to suck up organisms from the sea floor.