Eschrichtioides

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Eschrichtioides
Temporal range: Pliocene
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Eschrichtioides Portis 1885.jpg
Eschrichtioides gastaldii, from Portis 1885
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Infraorder: Cetacea
Family: Eschrichtiidae
Genus:† Eschrichtioides
Bisconti 2008
Species

†E. gastaldii
Strobel 1881

Synonyms

Eschrichtioides is an extinct genus of baleen whale known from the early Pliocene of northern Italy. Its type species, E. gastaldii, had a complex taxonomic history, starting as a cetothere, then as an extinct member of Balaenoptera , before being finally recognized as a relative of the gray whale.

Contents

Distribution

Eschrichtioides is one of two Eschrichtius relatives known from the Neogene of Italy, the other being Archaeschrichtius . Its holotype, MRSN 13802, comes from the early Pliocene-age Sabbie d'Asti Formation of the Piedmont region in Italy [1] and it is currently exposed in Asti's paleontological museum "Museo Paleontologico Territoriale dell'Astigiano" [2] .

Classification

Mandible, skull, and postcranial elements of Eschrichtioides gastaldii from Portis 1885 Eschrichtioides Portis 1885 fig 2.jpg
Mandible, skull, and postcranial elements of Eschrichtioides gastaldii from Portis 1885

Like other cetaceans from the Italian Pliocene, the classification of Eschrichtioides was highly contentious.

Brandt 1873 [3] described several species of Cetotherium from the Pliocene of northern Italy, including C. cortesi based on a specimen (MSRN  13802) found by Italian geologist Giuseppe Cortesi in 1816 near the town Cortandone ( 45°00′N8°06′E / 45.0°N 8.1°E / 45.0; 8.1 : paleocoordinates 44°54′N8°00′E / 44.9°N 8.0°E / 44.9; 8.0 ) [4]

Cortesi 1819 [5] described how he, after a day of searching for fossils, found what he first thought was a small piece of wood in a small river. After a closer inspection it proved to be a bone, and Cortesi and his companion found more and more of them in the banks of the river. After four days of digging they had unveiled a giant skeleton easily identifiable as a whale 12 feet 5 inches long. The three feet long head and its dentaries had no signs of either teeth nor tooth sockets. Cortesi noted that at that time few naturalists could assign cetacean fossils to individual species, and he therefore never named his specimen.

Desmoulins 1822 [6] thought the "Baleine de Cortesi" represented a distinctive species because it was a very small adult individual and because the curvature of the maxillary branches was less convex than in any other known whale. Other French naturalists [7] named it "Le rorqual de Cortési"; arguing that both Cortesi's fossil whales ("rorqual de Cortési" and "de Cuvier") were closely related to extant rorquals and the only difference between them was the much smaller size of the former.

Brandt 1873 [8] assigned the "baleine de Cortesi" to his own genus Cetotherium Cortesii.

In a preliminary note Strobel 1875 [9] pointed out differences in cranial morphology in two skulls both described as "Cetotherium cortesii" (a species named and described by Brandt 1873), and he therefore proposed the new specific name "Cetotherium gastaldii" (in honour of Italian palaeontologist Bartolomeo Gastaldi) for one of the specimens. Strobel 1881 [10] described the specimen and reiterated his arguments from 1875.

Originally misidentified as the balaenopterid "Balaena" cortesii, Brandt 1873 described "B." cortesii as a species of Cetotherium. [8] Strobel 1875 finally named it C. gastaldii. [11] However, several authors considered it to be referrable to Balaenoptera , [12] a taxonomic arrangement which was accepted for more than a century. [13] [14] However, re-examination of MRSN 13802 revealed that "C." gastaldii was not a balaenopterid and instead constituted its own genus within Eschrichtiidae. [1]

Related Research Articles

<span class="mw-page-title-main">Eschrichtiidae</span> Family of mammals

Eschrichtiidae or the gray whales is a family of baleen whale with a single extant species, the gray whale, as well as three described fossil genera: Archaeschrichtius and Eschrichtioides from the Miocene and Pliocene of Italy respectively, and Gricetoides from the Pliocene of North Carolina. More recent phylogenetic studies have found this family to be invalid, with its members nesting inside the Balaenopteridae. The names of the extant genus and the family honours Danish zoologist Daniel Eschricht.

<span class="mw-page-title-main">Rorqual</span> Family of mammals

Rorquals are the largest group of baleen whales, comprising the family Balaenopteridae, which contains ten extant species in three genera. They include the largest known animal that has ever lived, the blue whale, which can reach 180 tonnes, and the fin whale, which reaches 120 tonnes ; even the smallest of the group, the northern minke whale, reaches 9 tonnes.

<span class="mw-page-title-main">Neobalaenidae</span> Family of mammals

Neobalaenidae is a family of baleen whales including the extant pygmy right whale. Although traditionally considered related to balaenids, recent studies by Fordyce and Marx (2013) and Ludovic Dutoit and colleagues (2023) have recovered the living pygmy right whale as a member of Cetotheriidae, making it the only extant cetotheriid. Not all authors agree with this placement.

<i>Balaenoptera</i> Genus of mammals

Balaenoptera is a genus of rorquals containing eight extant species. Balaenoptera comprises all but two of the extant species in its family ; the genus is currently polyphyletic, with the two aforementioned species being phylogenetically nested within it.

<i>Cetotherium</i> Extinct genus of mammals

Cetotherium is an extinct genus of baleen whales from the family Cetotheriidae.

Parabalaenoptera is a genus of prehistoric baleen whale found in Marin County, California. The type species is P. baulinensis. It was estimated to be about the size of the modern gray whale, about 16 metres (52 ft) long. It lived during the late Miocene.

<i>Plesiobalaenoptera</i> Extinct genus of mammals

Plesiobalaenoptera is a genus of extinct rorqual which existed in Italy during the late Miocene epoch. The type species is P. quarantellii. It is the oldest known rorqual from the Mediterranean basin. Fossils have been found from sediments of the Stirone River in northern Italy that were deposited during the Tortonian age, around 11 to 7 million years ago.

Diunatans is an extinct genus of rorqual. It lived in the North Sea during the Early Pliocene. Two specimens have been found from the Netherlands. They were collected from the Kattendijk Formation in the province of Zeeland, which is Zanclean in age. Diunatans is considered to be a stem balaenopterid because it falls outside the Balaenoptera+Megaptera clade, which includes all living rorquals.

<span class="mw-page-title-main">Cetotheriidae</span> Family of mammals

Cetotheriidae is a family of baleen whales. The family is known to have existed from the Late Oligocene to the Early Pleistocene before going extinct. Although some phylogenetic studies conducted by Fordyce & Marx 2013 recovered the living pygmy right whale as a member of Cetotheriidae, making the pygmy right whale the only living cetotheriid, other authors either dispute this placement or recover Neobalaenidae as a sister group to Cetotheriidae.

<i>Parietobalaena</i>

Parietobalaena is an extinct genus of baleen whale, belonging to the family Pelocetidae. Fossils are found in Miocene-aged marine strata in North America, Europe, Australia, and Japan, including the Temblor and Itahashi formations. Based on previous estimates of juvenile specimens, Tsai (2017) suggested a body size of 12-15 m for P. yamaokai, akin to that of the gray whale.

<i>Piscobalaena</i> Extinct genus of mammals

Piscobalaena is an extinct genus of cetaceans, which lived from the Middle to Late Miocene epochs in Peru and Florida. Its fossils have been found in the Pisco Formation of Peru and the Bone Valley Formation of Florida. At least some individuals of this diminutive whale were preyed on by the shark O. megalodon.

<i>Herpetocetus</i> Extinct genus of mammals

Herpetocetus is a genus of cetotheriid mysticete in the subfamily Herpetocetinae.

<i>Protororqualus</i> Extinct genus of mammals

Protororqualus is a genus of extinct rorqual from the late Pliocene of Mount Pulgnasco, Italy.

<i>Cetotheriophanes</i> Extinct genus of mammals

Cetotheriophanes is an extinct rorqual from the late Pliocene (Piacenzian) of northern Italy.

<i>Archaebalaenoptera</i> Extinct genus of mammals

Archaebalaenoptera is a genus of extinct rorqual known from late Miocene to Pliocene-age marine deposits of the Netherlands, northern Italy, and Peru.

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.

<i>Cetotheriopsis</i> Extinct genus of cetaceans

Cetotheriopsis is a genus of extinct cetaceans of the family Cetotheriopsidae.

<i>Aglaocetus</i> Extinct genus of mammals

Aglaocetus is a genus of extinct baleen whales known from the Miocene of Patagonia, the US Eastern Seaboard, Japan and the Low Countries. It was once considered a member of Cetotheriidae along with many other putative cetotheres, but was recently recognized as representing a distinct family from true Cetotheriidae.

Fragilicetus is an extinct genus of rorqual from Early Pliocene deposits in Belgium.

References

Notes

  1. 1 2 Bisconti 2008
  2. ↑ https://www.astipaleontologico.it/la-balena-grigia-e-il-delfino-di-cortandone/
  3. ↑ Brandt 1873 , pp. 153–156
  4. ↑ "Cortandone (Pliocene of Italy)". Fossilworks. Retrieved 17 December 2021.
  5. ↑ Cortesi 1819 , pp. 61–67
  6. ↑ Desmoulins 1822 , p. 165
  7. ↑ Boitard 1861 , p. 443; Gervais 1867 , p. 461
  8. 1 2 Brandt 1873 , pp. 153–156̣
  9. ↑ Strobel 1875 , p.136
  10. ↑ Strobel 1881 , pp. 29–31
  11. ↑ Strobel 1875 , p. 136
  12. ↑ Portis 1885 , p. 17
  13. ↑ For example Trouessart 1904 , p. 782
  14. ↑ Deméré 1986

Sources

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