Temporal range: Late Oligocene - Holocene
|Specimen of Gomphotherium productum at the AMNH|
|Notiomastodon platensis Centro Cultural del Bicentenario de Santiago del Estero in Argentina|
(Hay, 1922) A. Cabrera 1929
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 following the Great American Interchange. Gomphotheriidae in its broadest sense is paraphyletic and 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 eastern 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.
The name "gomphothere" comes from Ancient Greek γόμφος (gómphos), "peg, pin; wedge; joint" plus θηρίον (theríon), "beast".
Gomphotheres differed from elephants in their tooth structure, particularly the chewing surfaces on the molar teeth. The teeth are considered to be bunodont, that is, having rounded cusps. They are thought to have chewed differently from modern elephants, using an oblique movement (combining back to front and side to side motion) over the teeth rather than the proal movement (a fowards stroke from the back to the front) used by modern elephants and stegodontids. Earlier gomphotheres had long lower jaws with lower tusks, similar to other primitive proboscideans. Later members developed shortened (brevirostrine) lower jaws and/or vestigial or no lower tusks.
"Gomphotheres" are assigned to their own family, Gomphotheriidae, but are widely agreed to be a paraphyletic group. The families Choerolophodontidae and Amebelodontidae (which includes "shovel tuskers" like Platybelodon), were formerly classified as gomphotheres sensu lato, but are now usually considered distinct. Gomphotheres are divided into two informal groups, "trilophodont gomphotheres", and "tetralophodont gomphotheres". "Trilophodont gomphotheres" are distinguished from "tetralophodont gomphotheres" by the presence of trefoil-shaped wear marks on the occusal surfaces of their teeth, while "tetralophodont gomphotheres" are distinguished by the presence of four ridges on the fourth premolar and on the first and second molars. Some authors choose to exclude "tetralophodont gomphotheres" from Gomphotheriidae, and instead assign them to the group Elephantoidea. "Tetralophodont gomphotheres" are thought to have evolved from "trilophodont gomphotheres", and are suggested to be ancestral to Elephantidae, the group which contains modern elephants, as well as Stegodontidae.
Molar of Gomphotherium angustidens, a "trilophodont gomphothere"
Molar of Anancus, a "tetralophodont gomphothere"
Gomphotheres are generally supposed to have mostly been browsers and mixed feeders, though some later species have been inferred to be grazers.
Gomphotheres originated in Africa during the Late Oligocene, and arrived in Eurasia after the connection of Africa and Eurasia during the Early Miocene around 19 million years ago, in what is termed the "Proboscidean Datum Event". Gomphotherium arrived in North America around 16 million years ago, and is suggested to be the ancestor of later New World gomphothere genera. "Trilophodont gomphotheres" dramatically declined during the Late Miocene, likely due to the increasing C4 grass-dominated habitats, while during the Late Miocene "tetralophodont gomphotheres" were abundant and widespread in Eurasia. All trilophodont gomphotheres, with the exception of the Asian Sinomastodon, became extinct in Eurasia by the beginning of the Pliocene. The New World gomphothere genera Notiomastodon and Cuvieronius dispersed into South America around or after 2.5 million years ago as part of the Great American Biotic Interchange due to the formation of the Isthmus of Panama. "Tetralophodont gomphotheres" became extinct in Africa around the end of the Pliocene and beginning of the Pleistocene. The last gomphothere native to Europe, the tetralophodont Anancus arvernensis became extinct during the Early Pleistocene, around 2-1.6 million years ago Sinomastodon became extinct at the end of the Early Pleistocene, around 800,000 years ago.
The extinction of gomphotheres in Afro-Eurasia has generally been supposed to be the result the expansion of Elephantidae and Stegodon. The morphology of elephantid molars being more efficient than gomphotheres in consuming grass, which became more abundant during the Pliocene and Pleistocene epochs. In the New World, gomphotheres did not become extinct until shortly after the arrival of humans to the Americas, approximately 12,000 years ago. Bones of gomphotheres in the Americas dating to shortly before their extinction have been found associated with human artifacts, suggesting that hunting may have played a role in their extinction.
- ^ Buckley, Michael; Recabarren, Omar P.; Lawless, Craig; García, Nuria; Pino, Mario (November 2019). "A molecular phylogeny of the extinct South American gomphothere through collagen sequence analysis". Quaternary Science Reviews. 224: 105882. Bibcode:2019QSRv..22405882B. doi:10.1016/j.quascirev.2019.105882.
- ^ Saegusa, Haruo (March 2020). "Stegodontidae and Anancus: Keys to understanding dental evolution in Elephantidae". Quaternary Science Reviews. 231: 106176. doi:10.1016/j.quascirev.2020.106176.
- ^ 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. 11 (1): e0147009. Bibcode:2016PLoSO..1147009M. doi:10.1371/journal.pone.0147009. PMC 4710528. PMID 26756209.
- ^ a b c Shoshani, J.; Tassy, P. (2005). "Advances in proboscidean taxonomy & classification, anatomy & physiology, and ecology & behavior". Quaternary International. 126–128: 5–20. Bibcode:2005QuInt.126....5S. doi:10.1016/j.quaint.2004.04.011.
- ^ Wang, Shi-Qi; Deng, Tao; Ye, Jie; He, Wen; Chen, Shan-Qin (2016). "Morphological and ecological diversity of Amebelodontidae (Proboscidea, Mammalia) revealed by a Miocene fossil accumulation of an upper-tuskless proboscidean". Systematic Palaeontology (Online ed.). 15 (8): 601–615. doi:10.1080/14772019.2016.1208687. S2CID 89063787.
- ^ 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. 11 (1): e0147009. Bibcode:2016PLoSO..1147009M. doi:10.1371/journal.pone.0147009. PMC 4710528. PMID 26756209.
- ^ Prado, Jos Luis; Alberdi, Mara Teresa (July 2008). "A CLADISTIC ANALYSIS AMONG TRILOPHODONT GOMPHOTHERES (MAMMALIA, PROBOSCIDEA) WITH SPECIAL ATTENTION TO THE SOUTH AMERICAN GENERA". Palaeontology. 51 (4): 903–915. doi:10.1111/j.1475-4983.2008.00785.x.
- ^ a b Wu, Yan; Deng, Tao; Hu, Yaowu; Ma, Jiao; Zhou, Xinying; Mao, Limi; Zhang, Hanwen; Ye, Jie; Wang, Shi-Qi (2018-05-16). "A grazing Gomphotherium in Middle Miocene Central Asia, 10 million years prior to the origin of the Elephantidae". Scientific Reports. 8 (1): 7640. doi:10.1038/s41598-018-25909-4. ISSN 2045-2322. PMC 5956065. PMID 29769581.
- ^ Sanders, W.J., Kappelman, J., and Rasmussen, D.T. 2004. New large-bodied mammals from the late Oligocene site of Chilga, Ethiopia. Acta Palaeontologica Polonica 49: 365–392.
- ^ a b Cantalapiedra, Juan L.; Sanisdro, Oscar L.; Zhang, Hanwen; Alberdi, Mª Teresa; Prado, Jose Luis; Blanco, Fernando; Saarinen, Juha (1 July 2021). "The rise and fall of proboscidean ecological diversity". Nature Ecology & Evolution. 355 (9): 1266–1272. doi:10.1038/s41559-021-01498-w. PMID 34211141. S2CID 235712060. Retrieved 21 August 2021 – via Escience.magazine.org.
- ^ Wang, Shi-Qi; Li, Yu; Duangkrayom, Jaroon; Yang, Xiang-Wen; He, Wen; Chen, Shan-Qin (2017-05-04). "A new species of Gomphotherium (Proboscidea, Mammalia) from China and the evolution of Gomphotherium in Eurasia". Journal of Vertebrate Paleontology. 37 (3): e1318284. doi:10.1080/02724634.2017.1318284. ISSN 0272-4634. S2CID 90593535.
- ^ Spencer LG 2022. The last North American gomphotheres. N Mex Mus Nat Hist Sci. 88:45–58.
- ^ Wang, Shi-Qi; Saegusa, Haruo; Duangkrayom, Jaroon; He, Wen; Chen, Shan-Qin (December 2017). "A new species of Tetralophodon from the Linxia Basin and the biostratigraphic significance of tetralophodont gomphotheres from the Upper Miocene of northern China". Palaeoworld. 26 (4): 703–717. doi:10.1016/j.palwor.2017.03.005.
- ^ a b Parray, Khursheed A.; Jukar, Advait M.; Paul, Abdul Qayoom; Ahmad, Ishfaq; Patnaik, Rajeev (March 2022). Silcox, Mary (ed.). "A gomphothere (Mammalia, Proboscidea) from the Quaternary of the Kashmir Valley, India". Papers in Palaeontology. 8 (2). doi:10.1002/spp2.1427. ISSN 2056-2799.
- ^ a b Mothé, Dimila; dos Santos Avilla, Leonardo; Asevedo, Lidiane; Borges-Silva, Leon; Rosas, Mariane; Labarca-Encina, Rafael; Souberlich, Ricardo; Soibelzon, Esteban; Roman-Carrion, José Luis; Ríos, Sergio D.; Rincon, Ascanio D.; Cardoso de Oliveira, Gina; Pereira Lopes, Renato (30 September 2016). "Sixty years after 'The mastodonts of Brazil': The state of the art of South American proboscideans (Proboscidea, Gomphotheriidae)" (PDF). Quaternary International. 443: 52–64. Bibcode:2017QuInt.443...52M. doi:10.1016/j.quaint.2016.08.028.
- ^ Sanders, William J.; Haile-Selassie, Yohannes (June 2012). "A New Assemblage of Mid-Pliocene Proboscideans from the Woranso-Mille Area, Afar Region, Ethiopia: Taxonomic, Evolutionary, and Paleoecological Considerations". Journal of Mammalian Evolution. 19 (2): 105–128. doi:10.1007/s10914-011-9181-y. ISSN 1064-7554.
- ^ Konidaris, George E.; Tsoukala, Evangelia (2022), Vlachos, Evangelos (ed.), "The Fossil Record of the Neogene Proboscidea (Mammalia) in Greece", Fossil Vertebrates of Greece Vol. 1, Cham: Springer International Publishing, pp. 299–344, doi:10.1007/978-3-030-68398-6_12, ISBN 978-3-030-68397-9, retrieved 2023-03-23
- ^ Konidaris, George E.; Roussiakis, Socrates J. (2018-11-02). "The first record of Anancus (Mammalia, Proboscidea) in the late Miocene of Greece and reappraisal of the primitive anancines from Europe". Journal of Vertebrate Paleontology. 38 (6): e1534118. doi:10.1080/02724634.2018.1534118. ISSN 0272-4634.
- ^ Rivals, Florent; Mol, Dick; Lacombat, Frédéric; Lister, Adrian M.; Semprebon, Gina M. (August 2015). "Resource partitioning and niche separation between mammoths (Mammuthus rumanus and Mammuthus meridionalis) and gomphotheres (Anancus arvernensis) in the Early Pleistocene of Europe". Quaternary International. 379: 164–170. doi:10.1016/j.quaint.2014.12.031.
- ^ Wang, Yuan; Jin, Chang-zhu; Mead, Jim I. (August 2014). "New remains of Sinomastodon yangziensis (Proboscidea, Gomphotheriidae) from Sanhe karst Cave, with discussion on the evolution of Pleistocene Sinomastodon in South China". Quaternary International. 339–340: 90–96. Bibcode:2014QuInt.339...90W. doi:10.1016/j.quaint.2013.03.006.
- ^ a b Lister, Adrian M. (August 2013). "The role of behaviour in adaptive morphological evolution of African proboscideans". Nature. 500 (7462): 331–334. doi:10.1038/nature12275. ISSN 0028-0836.
- "Buried Treasure in the Sierra Nevada Foothills". Sierra College. (article about a fossil exhibit at the Sierra College Natural History Museum)
- "Gomphothere description including images". Sierra College.
- ""King Tusk" Gomphothere Excavation". Sierra College. (photos from the excavation of a Gomphothere skeleton on the Sierra College website)
- "The Gomphotheriidae". University of California Museum of Paleontology.