Named By: Glikman - 1958.
Synonyms: Lamna appendiculata, Lamna appendiculatus, Otodus appendiculatus.
Classification: Chordata, Chondrichthyes, Elasmobranchii, Selachimorpha, Lamniformes.
Species: C. appendiculata, C. appendiculata appendiculata, C. appendiculata pachyrhiza, C. aschersoni, C. biauriculata, C. bryanti, C. feldmanni, C. gunsoni, C. lata, C. maroccana, C. pachyrhiza.
Size: Average length seems to have been anywhere between 2 to 3 meters, though rare examples indicate an upper size approaching 3.6 meters long.
Known locations: Fossils are literally known in age appropriate marine deposits worldwide.
Time period: Roughly Barremian of the Cretaceous to the Mid Miocene.
Fossil representation: Mostly teeth and vertebrae.
the Cretolamna shark
genus is extinct today,
there is no doubt that
it was one of the most successful of all shark genera. Fossils of
Cretolamna (mostly of teeth and vertebrae) are
known from all over
the world and range from the early Cretaceous to the mid Miocene in
age, making Cretolamna one of the most widely
genera in not just geographical range but throughout time as well.
Only a few other shark genera such as Hybodus
can claim to rival this
success. Because the first fossils of Cretolamna
were found in
Cretaceous aged deposits, the genus was given a name which means
‘Cretaceous Lamna’, with the Lamna part referencing the similarity
to the Lamna shark genus, which is the type genus
of the Lamniformes
group of sharks (The group that includes many modern kinds such as
the great white, thresher shark, porbeagle, mako, etc).
Cretolamna would have looked much like modern day lamniform sharks, and likely would have been a pelagic (open water) predator of other fish. However, Cretolamna living before the KT extinction during the Cretaceous and would have had the option to hunt marine reptiles such as plesiosaurs and smaller mosasaurs, while those living after the KT extinction may have attacked primitive cetaceans, many of which were much smaller than those we know today. The teeth of Cretolamna are broad with cusps at the base of the main crown, indicating that Cretolamna was best suited to attacking larger prey.
It is hard to be certain about exactly which different evolutionary lines that different sharks evolved from. However in the past the Cretolamna genus has been speculated to be the origin of other large predatory sharks, including the genera Otodus, and Paleocarcharodon. Paleocarcharodon is regarded as a possible ancestor to Carcharodon carcharias, today better known as the great white shark, and largest predatory shark alive today (basking and whale sharks are larger but these are filter feeders). Otodus however may have been the progenitor of the Carcharocles genus which includes such behemoths as C. angustidens, C. auriculatus, C. chubutensis, and largest of all, C. megalodon.
- Skeletal and dental anatomy of lamniform shark, Cretalamna appendiculata, from Upper Cretaceous Niobrara Chalk of Kansas - Journal of Vertebrate Paleontology vol 27, Issue 3 - Kenshu Shimada - 2007.
- Late Cretaceous (Cenomanian-Campanian) mid-palaeolatitude sharks of Cretalamna appendiculata type - Acta Palaeontologica Polonica. - Mikael Siverson, Johan Lindgren, Michael G. Newbrey, Peter Cederström & Todd D. Cook - 2013.
- Cenomanian–Campanian (Late Cretaceous) mid-palaeolatitude sharks of Cretalamna appendiculata type. - Acta Palaeontologica Polonica. 60 (2): 339–384. - Mikael Siversson, Johan Lindgren, Michael G. Newbrey, Peter Cederström & Todd D. Cook - 2015.
- A new species of Cretalamna sensu stricto (Lamniformes, Otodontidae) from the Late Cretaceous (Santonian-Campanian) of Alabama, USA. - PeerJ. 6 (e4229). - Jun A. Ebersole & Dana J. Ehret - 2018.