genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...
of extinct
rorqual
Rorquals () are the largest group of baleen whales, which comprise the family Balaenopteridae, containing ten extant species in three genera. They include the largest animal that has ever lived, the blue whale, which can reach , and the fin ...
from the late
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Piacenzian, ) of Mount Pulgnasco,
Italy
Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...
(: paleocoordinates ).
The analysis made by identified ''Protororqualus'' as a late representative of the rorquals which survived in the Mediterranean at least until the late Pliocene. This would indicate that the Mediterranean basin played a vital role in preserving primitive rorquals while more derived forms established themselves in other oceans.
Anatomy
The Mount Pulgnasco specimen represents an early rorqual that fed differently from modern species. Compared to the laterally bowed dentaries of the latter, its dentary is more straight, which should have made it impossible to perform the intermittent ram feeding seen in modern rorquals. Another primitive character is that the anterior border of the supraoccipital is triangular and pointed like in Miocene
Cetotheriidae
Cetotheriidae is a family of baleen whales (parvorder Mysticeti). The family is known to have existed from the Late Oligocene to the Early Pleistocene before going extinct. Although some phylogenetic studies conducted by recovered the living ...
.
Taxonomic history
The type species, ''Protorqualus cuvierii'', was originally described in 1829 as a species of ''Balaena'', but later transferred to the Belgian genus ''
Plesiocetus
''Plesiocetus'' is a genus of extinct balaenopterids found worldwide. It has had a chequered taxonomic history, having served as a wastebasket genus for a handful of mysticete species.
Taxonomy
The genus ''Plesiocetus'' was originally coined f ...
''. Following synonymy of ''Plesiocetus'' with ''Balaenoptera'', ''B. cuvieri'' was considered a species of ''
Balaenoptera
''Balaenoptera'' () is a genus of rorquals containing eight extant species. ''Balaenoptera'' comprises all but two of the extant species in its family (the humpback whale and gray whale); the genus is currently polyphyletic, with the two aforemen ...
'', although some authors treated it as a species of ''
Cetotherium
''Cetotherium'' ("whale beast") is an extinct genus of baleen whales from the family Cetotheriidae.
Taxonomy
The family Cetotheriidae and the genus ''Cetotherium'' (sensu lato) have been used as wastebaskets for all kinds of baleen whales, mo ...
''. Later work, however, showed that the Mount Pulgnasco skeleton was generically distinct from other fossil and extant rorquals to warrant its own genus.