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Squalodon protervus

Mammalia - Artiodactyla - Squalodontidae

Taxonomy
Cynorca proterva was named by Cope (1867) [genotype]. It is not extant. Its type specimen is ANSP 11543a.

It was recombined as Squalodon protervus by Cope (1867), Leidy (1869), Zittel (1894), Trouessart (1898), Hay (1902), Trouessart (1904) and Case (1904); it was considered a nomen dubium by Dal Piaz (1916); it was considered a nomen dubium by Wright and Eshelman (1987), Wright (1998), Albright (1999) and Fordyce (2002); it was considered a nomen nudum by Dooley (2003); it was recombined as Dicotyles protervus by Uhen et al. (2008).

Sister species lacking formal opinion data

View classification of included taxa

Synonyms
  • Dicotyles torquatus was named by Cope (1867).

    It was synonymized subjectively with Cynorca proterva by Woodburne (1969).
  • Dicotyles lenis was named by Leidy (1869) [specimens may belong to multiple individuals]. Its type specimen is ANSP 11543, a mandible (upper and lower canines, fragmentary left mandibular ramus, and lower m1), and it is a 3D body fossil.

    It was synonymized subjectively with Mylohyus fossilis by Lundelius (1960); it was synonymized subjectively with Cynorca proterva by Woodburne (1969).
Synonymy list
YearName and author
1867Squalodon protervus Cope
1867Cynorca proterva Cope p. 144
1867Dicotyles torquatus Cope p. 155
1867Cynorca proterva Cope p. 1868 fig. 151
1869Dicotyles lenis Leidy
1869Squalodon protervus Leidy p. 423
1894Squalodon protervus Zittel p. 171
1898Squalodon protervus Trouessart p. 1015
1902Squalodon protervus Hay p. 589
1904Squalodon protervus Case p. 7
1904Squalodon protervus Trouessart p. 756
1969Cynorca proterva Woodburne p. 287
1984Cynorca proterva Whitmore p. 238
2008Dicotyles protervus Uhen et al. p. 584

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RankNameAuthor
kingdomAnimalia()
Triploblastica
Nephrozoa
Deuterostomia
phylumChordataHaeckel 1847
subphylumVertebrata
superclassGnathostomata
Osteichthyes()
Sarcopterygii
subclassDipnotetrapodomorpha(Nelson 2006)
subclassTetrapodomorpha()
Tetrapoda()
Reptiliomorpha
Anthracosauria
Batrachosauria()
Cotylosauria()
Amniota
Synapsida()
RankNameAuthor
Therapsida()
infraorderCynodontia()
Epicynodontia
infraorderEucynodontia
Probainognathia
Mammaliamorpha
Mammaliaformes
classMammalia
orderArtiodactyla()
Cetacea()
Pelagiceti
Neoceti
Odontoceti()
superfamilyPlatanistoidea
familySqualodontidae
genusSqualodon
speciesprotervus()

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.

Diagnosis
ReferenceDiagnosis
M. O. Woodburne 1969Cranium small, rostrum probably moderately elongate; postzygomatic crest probably continuous with lambdoidal crest; supraorbital canals converging anterior to supraorbital foramina; auditory bullae filled with cancellous tissue, bullae not smoothly globose as in Thinohyus or Perchoerus, but anteriorly acuminate, with even, lightly sulcate, external surface as in Recent genera; central axis of bulla directed anteroventrally rather than anteromedially, posttympanic process of squamosal sulcate as in primitive genera, not flat as in Dyseohyus and later genera; glenoid fossa with distinct lateral edge, not merging smoothly and gradually with lateral surface of tympanic process of squamosal as in primitive peccaries; glenoid fossa lower relative to ventral edge of bulla than in earliest of primitive genera; base of paroccipital process aligned nearly longitudinally; infraorbital foramen above P4, cross section subovate to slitlike; amount of facial exposure of lacrimal small; anterior palatine foramina occurring between MI and M2; upper diastemal crest forming medial border of elongate, but relatively narrow, ventrally facing, buccinator fossa; diastema between C' and PI relatively greater than in primitive genera; diastema between C' and p2 about equal to combined length of P2-P4; dental formula I", C, pI-?4, M'; F considerably larger than I2, IF and J2 slanting anteroventrally, I3 directed nearly vertically; C' with only faint lingual grooves and lateral ridges; p1 small, reduced when present; p2 and P3 with single, rounded main cusp and wide talon; P4 subtriangular, incipiently molariform, protocone separated from metaconule by posterolingually directed postprotoconal groove in some species; upper molars with moderate to strongly expanded lingual bases; in width MIM3; M3 variably reduced; lower incisors extending anteriorly, I2 lying posterolateral to I1; I, and I2 subconical in cross section; lower canine with lateral ridges and lingual grooves developed only about halfway up from the alveolus; distance between canine and P2 about 20 per cent longer than combined length of P2-P4; talonid of P2 poorly developed; P3 with incipient anterior basal cuspid, undivided main cuspid, and poorly developed talonid; P4 with moderately broad anterior end, talonid narrow, small, and low; lower diastemal crests narrow but not sharp; in width MI < M2 > Ms; rami elongate, slender; postdigastric sulcus shallow; angle inflected; pterygoid and digastric fossae confluent; digastric fossa well developed.