Anancus

{{Automatic taxobox

| fossil_range = {{Fossil range|Late Miocene|Early Pleistocene}}

| image = Anancus arvernensis.JPG

| image_caption = One of the most complete A. arvernensis skeletons found clay layers near San Giovanni Valdarno and displayed in the Museo di Storia Naturale di Firenze in Tuscany, Italy

| taxon = Anancus

| authority = Aymard, 1855

| subdivision_ranks = Species

| subdivision = * A. alexeevae Baigusheva, 1971

A. arvernensis (Croizet and Jobert, 1828) (type)
A. capensis Sanders, 2007
A. cuneatus Teilhard de Chardin and Trassaert, 1937
A. kazachstanensis Aubekerova, 1974
A. kenyensis MacInnes, 1942
A. lehmanni (Gaziry, 1997)
A. osiris Arambourg, 1945
A. perimensis (Falconer and Cautley, 1847)
A. petrocchii Coppens, 1965
A. sinensis Hopwood, 1935
A. sivalensis (Cautley, 1836)
A. ultimus Sanders, 2011

}}

Anancus is an extinct genus of "tetralophodont gomphothere" native to Afro-Eurasia, that lived from the Tortonian stage of the late Miocene until its extinction during the Early Pleistocene, roughly from 8.5–2 million years ago.

Taxonomy

Anancus was named by Auguste Aymard in 1855. It is traditionally allocated to Gomphotheriidae, often as the only member of the subfamily Anancinae.{{cite journal |last1=Hautier |first1=Lionel |last2=Mackaye |first2=Hassane Taisso |last3=Lihoreau |first3=Fabrice |last4=Tassy |first4=Pascal |last5=Vignaud |first5=Patrick |last6=Brunet |first6=Michel |title=New material of Anancus kenyensis (proboscidea, mammalia) from Toros-Menalla (Late Miocene, Chad): Contribution to the systematics of African anancines |journal=Journal of African Earth Sciences |date=March 2009 |volume=53 |issue=4–5 |pages=171–176 |doi=10.1016/j.jafrearsci.2009.01.003 |bibcode=2009JAfES..53..171H }}{{Citation |last1=Konidaris |first1=George E. |title=The Fossil Record of the Neogene Proboscidea (Mammalia) in Greece |date=2022 |url=https://link.springer.com/10.1007/978-3-030-68398-6_12 |work=Fossil Vertebrates of Greece Vol. 1 |pages=299–344 |editor-last=Vlachos |editor-first=Evangelos |access-date=2023-04-18 |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-030-68398-6_12 |isbn=978-3-030-68397-9 |last2=Tsoukala |first2=Evangelia|s2cid=245023119 |url-access=subscription }} Recently, some authors have excluded Anancus along with other tetralophodont gomphotheres from Gomphotheriidae, and regarded them as members of Elephantoidea instead.{{cite journal |last1=Shoshani |first1=Jeheskel |last2=Tassy |first2=Pascal |title=Advances in proboscidean taxonomy & classification, anatomy & physiology, and ecology & behavior |journal=Quaternary International |date=January 2005 |volume=126-128 |pages=5–20 |doi=10.1016/j.quaint.2004.04.011 |bibcode=2005QuInt.126....5S }}{{cite book |authorlink1=Jeheskel Shoshani |first1=J. |last1=Shoshani |first2=P. |last2=Tassy |year=1996 |chapter=Summary, conclusions, and a glimpse into the future |pages=335–348 |editor1-last=Shoshani |editor1-first=Jeheskel |editor2-last=Tassy |editor2-first=Pascal |title=The Proboscidea: Evolution and Palaeoecology of Elephants and Their Relatives |publisher=Oxford University Press |isbn=978-0-19-854652-8 }}{{cite journal |last1=Mothé |first1=Dimila |last2=Ferretti |first2=Marco P. |last3=Avilla |first3=Leonardo S. |title=The Dance of Tusks: Rediscovery of Lower Incisors in the Pan-American Proboscidean Cuvieronius hyodon Revises Incisor Evolution in Elephantimorpha |journal=PLOS ONE |date=12 January 2016 |volume=11 |issue=1 |pages=e0147009 |doi=10.1371/journal.pone.0147009 |pmid=26756209 |pmc=4710528 |bibcode=2016PLoSO..1147009M |doi-access=free }}

Description

File:Anancus NT small.jpg

File:Anancus skull.png

Two largely complete individuals of Anancus arvernensis reached shoulder heights of around {{convert|2.5-2.6|m}}, with a volumetric estimate suggesting a body mass of around {{Convert|5.2 to 6|t|lb}}, comparable to living African bush elephants.{{Cite journal |last1=Romano |first1=Marco |last2=Bellucci |first2=Luca |last3=Antonelli |first3=Matteo |last4=Manucci |first4=Fabio |last5=Palombo |first5=Maria Rita |date=2023-06-13 |title=Body mass estimate of Anancus arvernensis (Croizet and Jobert 1828): comparison of the regression and volumetric methods |url=https://onlinelibrary.wiley.com/doi/10.1002/jqs.3549 |journal=Journal of Quaternary Science |volume=38 |issue=8 |pages=1357–1381 |language=en |doi=10.1002/jqs.3549 |bibcode=2023JQS....38.1357R |s2cid=259438457 |issn=0267-8179|url-access=subscription }} The tusks were largely straight and lacked enamel (though enamel was present in juvenilesTheodorou, G., Spjeldnaes, N., Hanken, N. M., Lauritzen, S. E., Velitzelos, E., Athanassiou, A., et al. (2000). Description and taphonomic investigations of Neogene Proboscidea from Rhodos, Greece. Annales Géologiques des Pays Helléniques, 38, 133–156.) and were slender, and proportionally large, with a large tusk of the species Anancus avernensis from Stoina, Romania measuring {{Convert|3.71|m|ft}} in length with an estimated mass of {{Convert|70|kg|lb}}.{{Cite journal |last=Larramendi |first=Asier |date=2023-12-10 |title=Estimating tusk masses in proboscideans: a comprehensive analysis and predictive model |url=https://www.tandfonline.com/doi/full/10.1080/08912963.2023.2286272 |journal=Historical Biology |language=en |pages=1–14 |doi=10.1080/08912963.2023.2286272 |issn=0891-2963|url-access=subscription }} The tusks varied from projecting forward parallel to each other, to being outwardly divergent from each other, depending on the species.{{Cite journal |last1=Konidaris |first1=George E. |last2=Roussiakis |first2=Socrates J. |date=2018-11-02 |title=The first record of Anancus (Mammalia, Proboscidea) in the late Miocene of Greece and reappraisal of the primitive anancines from Europe |url=https://www.tandfonline.com/doi/full/10.1080/02724634.2018.1534118 |journal=Journal of Vertebrate Paleontology |language=en |volume=38 |issue=6 |pages=e1534118 |doi=10.1080/02724634.2018.1534118 |bibcode=2018JVPal..38E4118K |s2cid=91391249 |issn=0272-4634|url-access=subscription }} The skull is proportionally tall and short, with an elevated dome and an enlarged tympanic bulla. Unlike more primitive gomphotheres, the mandible was brevirostrine (shortened), and lacked lower tusks. The skull of Anancus species is very similar to living elephants and like them they probably had free-hanging (pendulous) trunks.{{Cite journal |last=Nabavizadeh |first=Ali |date=2024-10-08 |title=Of tusks and trunks: A review of craniofacial evolutionary anatomy in elephants and extinct Proboscidea |url=https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/ar.25578 |journal=The Anatomical Record |language=en |doi=10.1002/ar.25578 |issn=1932-8486|url-access=subscription }} The molars were typically tetralophodont (bearing four crests or ridges) but were pentalophodont in some species. The premolars were absent in all species other than A. kenyensis. On the upper molars, the posterior pretrite central conules were reduced, as were the anterior pretrite central conules on the lower molars. The pretrite and posttrite half-loph(id)s were dislocated from each other, resulting in the successive loph(id)s exhibiting an alternating pattern.{{Cite journal |last1=Konidaris |first1=George E. |last2=Roussiakis |first2=Socrates J. |date=2018-11-02 |title=The first record of Anancus (Mammalia, Proboscidea) in the late Miocene of Greece and reappraisal of the primitive anancines from Europe |url=https://www.tandfonline.com/doi/full/10.1080/02724634.2018.1534118 |journal=Journal of Vertebrate Paleontology |language=en |volume=38 |issue=6 |pages=e1534118 |doi=10.1080/02724634.2018.1534118 |bibcode=2018JVPal..38E4118K |issn=0272-4634 |s2cid=91391249|url-access=subscription }}

Diet

Dietary preferences of Anancus varied between species. Dental microwear analysis of Anancus arvernensis specimens from the Early Pleistocene of Europe generally suggests that it was a browser, consuming twigs, bark, seeds and fruit,{{Cite journal |last1=Rivals |first1=Florent |last2=Mol |first2=Dick |last3=Lacombat |first3=Frédéric |last4=Lister |first4=Adrian M. |last5=Semprebon |first5=Gina M. |date=2015-08-27 |title=Resource partitioning and niche separation between mammoths (Mammuthus rumanus and Mammuthus meridionalis) and gomphotheres (Anancus arvernensis) in the Early Pleistocene of Europe |url=https://www.sciencedirect.com/science/article/pii/S1040618214009860 |journal=Quaternary International |series=Mammoths and their Relatives: VIth International Conference, Grevena-Siatista, Greece, part 1 |language=en |volume=379 |pages=164–170 |doi=10.1016/j.quaint.2014.12.031 |bibcode=2015QuInt.379..164R |issn=1040-6182|url-access=subscription }} with a browsing diet also proposed for the Early Pliocene South African A. capensis.{{Cite journal |last1=Groenewald |first1=Patricia A. |last2=Sealy |first2=Judith |last3=Stynder |first3=Deano |last4=Smith |first4=Kathlyn M. |date=April 2020 |title=Dietary resource partitioning among three coeval proboscidean taxa (Anancus capensis, Mammuthus subplanifrons, Loxodonta cookei) from the South African Early Pliocene locality of Langebaanweg E Quarry |url=https://linkinghub.elsevier.com/retrieve/pii/S003101821930851X |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |language=en |volume=543 |pages=109606 |doi=10.1016/j.palaeo.2020.109606|bibcode=2020PPP...54309606G |s2cid=213999549 |url-access=subscription }} The East African late Miocene-early Pliocene A. kenyensis and Pliocene A. ultimus have individuals with varying browsing, grazing, and mixed feeding (both browsing and grazing) diets,{{Cite journal |last1=Saarinen |first1=Juha |last2=Lister |first2=Adrian M. |date=2023-08-14 |title=Fluctuating climate and dietary innovation drove ratcheted evolution of proboscidean dental traits |journal=Nature Ecology & Evolution |volume=7 |issue=9 |pages=1490–1502 |language=en |doi=10.1038/s41559-023-02151-4 |issn=2397-334X|doi-access=free |pmid=37580434 |pmc=10482678 |bibcode=2023NatEE...7.1490S }} with a grazing diet proposed for Anancus specimens from the Pliocene of India based on isotopic analysis.{{Cite journal |last1=Patnaik |first1=Rajeev |last2=Singh |first2=Ningthoujam Premjit |last3=Paul |first3=Debajyoti |last4=Sukumar |first4=Raman |date=November 2019 |title=Dietary and habitat shifts in relation to climate of Neogene-Quaternary proboscideans and associated mammals of the Indian subcontinent |url=https://linkinghub.elsevier.com/retrieve/pii/S027737911930263X |journal=Quaternary Science Reviews |language=en |volume=224 |pages=105968 |doi=10.1016/j.quascirev.2019.105968|bibcode=2019QSRv..22405968P |s2cid=210307849 |url-access=subscription }} Anancus osiris from the Pliocene of North Africa is suggested to have been a mixed feeder with a large grass intake based on microwear.{{Cite journal |last1=Ramírez-Pedraza |first1=Iván |last2=Rivals |first2=Florent |last3=Tornero |first3=Carlos |last4=Geraads |first4=Denis |last5=Raynal |first5=Jean Paul |last6=Lefèvre |first6=David |last7=Mohib |first7=Abderrahim |date=November 2023 |title=Palaeoecological reconstruction of Plio-Pleistocene herbivores from the Ahl al Oughlam site (Casablanca, Morocco): Insights from dental wear and stable isotopes |url=https://linkinghub.elsevier.com/retrieve/pii/S027737912300389X |journal=Quaternary Science Reviews |language=en |volume=319 |pages=108341 |doi=10.1016/j.quascirev.2023.108341|bibcode=2023QSRv..31908341R |s2cid=263714029 }}

Evolution

Anancus is suggested to have evolved from Tetralophodon or a Tetralophodon-like ancestor.{{Cite journal |last=Athanassiou |first=Athanassios |date=June 2016 |title=Craniomandibular remains of Anancus arvernensis (Proboscidea, Mammalia) from Greece: The samples from Kallíphytos (E. Macedonia) and Sésklo (Thessaly) |url=https://linkinghub.elsevier.com/retrieve/pii/S1040618215002451 |journal=Quaternary International |language=en |volume=406 |pages=25–34 |doi=10.1016/j.quaint.2015.03.048|bibcode=2016QuInt.406...25A |url-access=subscription }} The oldest known species of Anancus is A. perimensis, with fossils known from the Tortonian ~ 8.5 million years ago Siwalik Hills of Pakistan. Anancus entered Europe approximately 7.2 million years ago and around 7 million years ago dispersed into Africa. Anancus first appeared in China around 6 million years ago (A. sinensis). Anancus disappeared from Asia and Africa around the end of the Pliocene, approximately 2.6 million years ago. The extinction of Anancus in Africa has been attributed to competitive exclusion by elephantids, whose molar teeth were more efficient at processing grass.{{Cite journal |last=Lister |first=Adrian M. |date=2013-06-26 |title=The role of behaviour in adaptive morphological evolution of African proboscideans |url=http://dx.doi.org/10.1038/nature12275 |journal=Nature |volume=500 |issue=7462 |pages=331–334 |doi=10.1038/nature12275 |issn=0028-0836 |pmid=23803767 |bibcode=2013Natur.500..331L |s2cid=883007|url-access=subscription }}{{Cite journal |last=Saegusa |first=Haruo |date=March 2020 |title=Stegodontidae and Anancus: Keys to understanding dental evolution in Elephantidae |url=https://linkinghub.elsevier.com/retrieve/pii/S0277379119302665 |journal=Quaternary Science Reviews |language=en |volume=231 |pages=106176 |bibcode=2020QSRv..23106176S |doi=10.1016/j.quascirev.2020.106176 |s2cid=214094348|url-access=subscription }} The European A. arvernensis was the last surviving species, becoming extinct during the Early Pleistocene, around 2 million years ago, with its latest possible record being at Eastern Scheldt in the Netherlands around 1.6 million years ago.