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Metasqualodon symmetricus

Mammalia - Cetacea

Taxonomy
Metasqualodon symmetricus was named by Okazaki (1982) [Kitakyushu Museum of Natural History]. Its type specimen is KMNH VP 000,004, a partial skull, and it is a 3D body fossil. Its type locality is Umashima Island, which is in a Chattian marine horizon in the Waita Formation of Japan.

It was considered a nomen dubium by Fordyce and de Muizon (2001).

Synonymy list
YearName and author
1982Metasqualodon symmetricus Okazaki p. 108 figs. Fig. 1, Plates 6-7
1985Metasqualodon symmetricus Okazaki p. 120
1987Metasqualodon symmetricus Okazaki p. 137
2017Metasqualodon symmetricus Geisler et al. p. 5 figs. Figure 4

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RankNameAuthor
kingdomAnimalia()
—Bilateria
—EubilateriaAx 1987
—Deuterostomia
phylumChordataHaeckel 1874
subphylumVertebrata
superclassGnathostomata
—Osteichthyes()
subclassSarcopterygii()
subclassDipnotetrapodomorpha(Nelson 2006)
subclassTetrapodomorpha()
—Tetrapoda
—Reptiliomorpha
—Anthracosauria
subclassAmphibiosauriaKuhn 1967
—Cotylosauria()
—Amniota
subclassSynapsida
—Therapsida()
infraorderCynodontia()
—Mammaliamorpha
RankNameAuthor
—Mammaliaformes
classMammalia
—Cladotheria
—Zatheria
subclassTribosphenida()
subclassTheria
—Eutheria()
—Placentalia
—Boreoeutheria
—Laurasiatheria
—Scrotifera
—Euungulata
—Artiodactylamorpha
—Artiodactyla()
—Whippomorpha
orderCetacea
—Pelagiceti
—Neoceti
suborderMysticeti
genusMetasqualodon
speciessymmetricus

If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.

†Metasqualodon symmetricus Okazaki 1982
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Diagnosis
No diagnoses are available
Measurements
No measurements are available
Composition: hydroxyapatitesubo
Form: roller-shapedo
Ontogeny: modification of partso
Environment: marinesubo
Locomotion: actively mobileo
Life habit: aquaticsubo
Depth habitat: surfaceo
Diet: carnivoresubo
Diet 2: suspension feedersubo
Reproduction: viviparouso
Created: 2005-03-06 14:20:41
Modified: 2005-03-06 16:34:40
Source: subo = suborder, o = order
Reference: Uhen 2004

Age range: Chattian or 28.10000 to 23.03000 Ma

Collections (5 total)


Time interval Ma Country or state Original ID and collection number
Late/Upper Oligocene28.4 - 23.03Japan (Yamaguchi) Metasqualodon symmetricus (51437)
Chattian28.1 - 23.03Japan (Fukuoka) Metasqualodon symmetricus (type locality: 45832 45833 45834) Squalodontidae indet. (45835)