Gnathabelodon

Last updated

Gnathabelodon
Temporal range: Middle Miocene–Late Miocene
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Proboscidea
Family: Gomphotheriidae
Subfamily: Gnathabelodontinae
Genus: Gnathabelodon
Barbour and Sternberg, 1935 [1]
Species:
G. thorpei
Binomial name
Gnathabelodon thorpei
Barbour and Sternberg, 1935

Gnathabelodon is an extinct genus of gomphothere (a sister group to modern elephants) endemic to North America that includes species that lived during the Middle to Late Miocene.

Contents

"Gnathabelodon" buckneri Sellards, 1940 has been renamed Blancotherium . [2]

Description

It has been called the "spoon-billed mastodon" since its lower jaw was elongated and shaped like a shoe-horn or spoon. The flaring of the tip of the lower jaw was similar to that of the "shovel-tuskers" ( Platybelodon and Amebelodon ); however, Gnathabelodon species are distinct in having no lower tusks whilst the "shovel tuskers" have broad, flattened lower tusks. The presence of a long lower jaw but no lower tusks is highly unusual among proboscideans, and only shared with Eubelodon and Choerolophodon. The upper tusks are large and curve outwards and upwards. With respect to dentition and overall body form, it was similar to species of Gomphotherium , but Mothe et al. (2016) recover Gnathabelodon as closer to brevirostrine gomphotheriids than to Gomphotherium. [3]

Taxonomy

While some studies have assigned the genus to Gomphotheriidae, [3] other have suggested that it may have closer affinities with Choerolophodontidae. [4]

Related Research Articles

<span class="mw-page-title-main">Proboscidea</span> Order of elephant-like mammals

Proboscidea is a taxonomic order of afrotherian mammals containing one living family (Elephantidae) and several extinct families. First described by J. Illiger in 1811, it encompasses the elephants and their close relatives. Three species of elephant are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant.

<span class="mw-page-title-main">Mastodon</span> Extinct genus of proboscideans

A mastodon is a member of the genus Mammut, which strictly defined, was endemic to North America and lived from the late Miocene to the early Holocene. Mastodons belong to the order Proboscidea, the same order as elephants and mammoths. Mammut is the type genus of the extinct family Mammutidae, which diverged from the ancestors of modern elephants at least 27-25 million years ago, during the Oligocene.

<span class="mw-page-title-main">Mammutidae</span> Extinct family of mammals

Mammutidae is an extinct family of proboscideans belonging to Elephantimorpha. It is best known for the mastodons, which inhabited North America from the Late Miocene until their extinction at beginning of the Holocene, around 11,000 years ago. The earliest fossils of the group are known from the Late Oligocene of Africa, around 24 million years ago, and fossils of the group have also been found across Eurasia. The name "mastodon" derives from Greek, μαστός "nipple" and ὀδούς "tooth", referring to their characteristic teeth.

<i>Platybelodon</i> Extinct genus of large herbivorous proboscidean mammals

Platybelodon is an extinct genus of large herbivorous proboscidean mammals related to modern-day elephants, placed in the "shovel tusker" family Amebelodontidae. Species lived during the middle Miocene Epoch in Africa, Asia and the Caucasus.

<span class="mw-page-title-main">Gomphothere</span> Extinct family of proboscidean mammals

Gomphotheres are an extinct group of proboscideans related to modern elephants. They were widespread across Afro-Eurasia and North America during the Miocene and Pliocene epochs and dispersed into South America during the Pleistocene as part of the Great American Interchange. Gomphotheres are a paraphyletic group that is ancestral to Elephantidae, which contains modern elephants, as well as Stegodontidae. While most famous forms such as Gomphotherium had long lower jaws with tusks, which is the ancestral condition for the group, some later members developed shortened (brevirostrine) lower jaws with either vestigial or no lower tusks, looking very similar to modern elephants, an example of parallel evolution, which outlasted the long-jawed gomphotheres. By the end of the Early Pleistocene, gomphotheres became extinct in Afro-Eurasia, with the last two genera, Cuvieronius ranging from southern North America to western South America, and Notiomastodon having a wide range over most of South America until the end of the Pleistocene around 12,000 years ago, when they became extinct following the arrival of humans.

<i>Prodeinotherium</i> Extinct genus of proboscideans

Prodeinotherium is an extinct representative of the family Deinotheriidae that lived in Africa, Europe, and Asia in the early and middle Miocene. Prodeinotherium, meaning "before terrible beast", was first named in 1930, but soon after, the only species in it, P. hungaricum, was reassigned to Deinotherium. During the 1970s, however, the two genera were once again separated, with Prodeinotherium diagnosed to include Deinotherium bavaricum, Deinotherium hobleyi, and Deinotherium pentapotamiae, which were separated based on geographic location. The three species are from Europe, Africa, and Asia, respectively. However, because of usage of few characters to separate them, only one species, P. bavaricum, or many more species, including P. cuvieri, P. orlovii, and P. sinense may be possible.

<i>Gomphotherium</i> Extinct genus of elephant-like mammals

Gomphotherium is an extinct genus of gomphothere proboscidean from the Neogene of Eurasia, Africa and North America. The genus is probably paraphyletic.

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

Cuvieronius is an extinct New World genus of gomphothere which ranged from southern North America to western South America during the Pleistocene epoch. Among the last gomphotheres, it became extinct at the end of the Pleistocene, approximately 12,000 years ago, following the arrival of humans to the Americas.

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

Stegomastodon is an extinct genus of gomphotheres. It ranged throughout North America from the Pliocene, to the Early Pleistocene. The former South American species have been synonymized with Notiomastodon platensis.

<i>Sinomastodon</i> Extinct genus of gomphothere proboscidean

Sinomastodon is an extinct gomphothere genus known from the Late Miocene to Early Pleistocene of Asia, including China, Japan, Thailand, Myanmar, Indonesia and probably Kashmir.

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

Tetralophodon is an extinct genus of "tetralophodont gomphothere" belonging to the superfamily Elephantoidea, known from the Miocene of Afro-Eurasia.

<i>Rhynchotherium</i> Extinct genus of proboscid

Rhynchotherium is an extinct genus of proboscidea endemic to North America and Central America during the Miocene through Pliocene from 13.650 to 3.6 Ma, living for approximately 10 million years.

<i>Eubelodon</i> Extinct genus of proboscid

Eubelodon is an extinct genus of gomphothere which lived in North America during the Miocene Epoch. It contains a single species: Eubelodon morrilli.

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

Notiomastodon is an extinct genus of gomphothere proboscidean, endemic to South America from the Pleistocene to the beginning of the Holocene. Notiomastodon specimens reached a size similar to that of the modern Asian elephant, with a body mass of 3-4 tonnes. Like other brevirostrine gomphotheres such as Cuvieronius and Stegomastodon, Notiomastodon had a shortened lower jaw and lacked lower tusks, unlike more primitive gomphotheres like Gomphotherium.

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

Choerolophodon is an extinct genus of proboscidean that lived during the Miocene of Eurasia and Africa. Fossils of Choerolophodon have been found in Africa, Southeast Europe, Turkey, Iraq, Iran, the Indian subcontinent, and China.

<span class="mw-page-title-main">Elephantimorpha</span> Clade of mammals

Elephantimorpha is a clade of proboscideans that contains the Mammutidae (mastodons), as well as Elephantida. All members of this group have the horizontal tooth replacement typical of modern elephants, unlike more primitive members of the Elephantiformes. Like modern elephants, the ancestor of Elephantimorpha was likely capable of communicating via infrasonic calls. While early elephantimorphs generally had lower jaws with an elongated mandibular symphysis at the front of the jaw with well developed lower tusks/incisors, from the Late Miocene onwards, many groups convergently developed brevirostrine (shortened) lower jaws with vestigial or no lower tusks, corresponding with the elongation and increasingly dexterity of the trunk allowing it to be used as the primary feeding organ.

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

Konobelodon is an extinct genus of amebelodont proboscidean from the Miocene of Africa, Eurasia and North America.

<span class="mw-page-title-main">Amebelodontidae</span> Extinct family of mammals

Amebelodontidae is an extinct family of large herbivorous proboscidean mammals related to elephants. They were formerly assigned to Gomphotheriidae, but recent authors consider them a distinct family. They are distinguished from other proboscideans by having flattened lower tusks and very elongate mandibular symphysis. The lower tusks could grow considerable size, with those of Konobelodon reaching 1.61 metres (5.3 ft) in length. Their molar teeth are typically trilophodont, and possessed posttrite conules. In the past, amebelodonts' shovel-like mandibular tusks led to them being portrayed scooping up water plants, however, dental microwear suggests that they were browsers and mixed feeders. The lower tusks have been proposed to have had a variety of functions depending on the species, including stripping bark, cutting through vegetation, as well as possibly digging. They first appeared in Africa during the Early Miocene, and subsequently dispersed into Eurasia and then North America. They became extinct by the beginning of the Pliocene. While some phylogenetic studies have recovered Amebelodontidae as a monophyletic group that forms the sister group to Gomphotheriidae proper, some authors have argued that Amebelodontidae may be polyphyletic, with it being suggested that the shovel-tusked condition arose several times independently within Gomphotheriidae, thus rendering the family invalid.

<span class="mw-page-title-main">Choerolophodontidae</span> Extinct family of mammals

Choerolophodontidae is an extinct family of proboscideans belonging to Elephantida. Two genera are widely recognised, Afrochoerodon and Choerolophodon.

Eurybelodon is an extinct genus of proboscidean in the family Amebelodontidae. It lived in the Clarendonian age of the Miocene.

References

  1. Barbour, E.H. and Sternberg, G. (1935). Gnathabelodon thorpei, gen. et sp. nov. A new mud-grubbing mastodon. Bulletin of the Nebraska State Museum, 42: 395-404.
  2. Steven R. May (2019). The Lapara Creek Fauna: Early Clarendonian of south Texas, USA. Palaeontologia Electronica 22 (1): Article number 22.1.15. doi:10.26879/929.
  3. 1 2 Mothé, Dimila; Ferretti, Marco P.; Avilla, Leonardo S. (12 January 2016). "The Dance of Tusks: Rediscovery of Lower Incisors in the Pan-American Proboscidean Cuvieronius hyodon Revises Incisor Evolution in Elephantimorpha". PLOS ONE. doi:10.1371/journal.pone.0147009. Retrieved 4 May 2017.
  4. CX LI, J CHEN, SQ WANG Reassessment of Trilophodon connexus Hopwood, 1935 and attributing it to the Choerolophodontidae Vertebrata PalAsiatica, 2024

Sources