Otodus chubutensis

{{speciesbox

| fossil_range = Early Miocene-Middle Miocene

| image = Carcharocles subauriculatus big.jpg

| image_caption = Partially preserved O. chubutensis broken tooth with a slant height of {{convert|129|mm|abbr=on}}

| genus = Otodus

| species = chubutensis

| authority = Ameghino, 1901

| synonyms = * Carcharodon mexicanus

Carcharocles chubutensis
Carcharodon chubutensis
Carcharodon productus
Megaselachus chubutensis {{small|Glikman, 1964}}
Otodus subauriculatus
Carcharocles subauriculatus
Procarcharodon subauriculatus
Carcharodon subauriculatus {{small|Agassiz, 1843}}
Carcharodon megalodon chubutensis
Carcharodon megalodon indica
Procarcharodon chubutensis
Otodus turgidus
Carcharocles turgidus
Carcharodon turgidus {{small|Agassiz, 1839}}

}}

Otodus chubutensis,{{cite journal|last1= Shimada|first1=K.|last2= Chandler|first2=R. E.|last3= Lam|first3=O. L. T.|last4= Tanaka|first4=T.|last5= Ward|first5=D. J.|title=A new elusive otodontid shark (Lamniformes: Otodontidae) from the lower Miocene, and comments on the taxonomy of otodontid genera, including the 'megatoothed' clade|journal= Historical Biology|volume=29|issue=5|year=2016|pages= 1–11|doi= 10.1080/08912963.2016.1236795|s2cid=89080495}} meaning "ear-shaped tooth of Chubut", from Ancient Greek ὠτ (ōt, meaning "ear") and ὀδούς (odoús, meaning "tooth") – thus, "ear-shaped tooth", is an extinct species of prehistoric megatoothed sharks in the genus Otodus, lived from Early Miocene to Middle Miocene.{{cite journal|first1=Harry M.|last1=Maisch IV|first2=Martin A.|last2=Becker|first3=John A.|last3=Chamberlain Jr.|year=2020|title=Macroborings in Otodus megalodon and Otodus chubutensis shark teeth from the submerged shelf of Onslow Bay, North Carolina, USA: implications for processes of lag deposit formation|journal=Ichnos|volume=27|issue=2|pages=122–141|doi=10.1080/10420940.2019.1697257|bibcode=2020Ichno..27..122M }} The largest individuals were about {{convert|13.5|m|ft}} long. This shark is considered a close relative of the famous prehistoric megatoothed shark O. megalodon.{{Cite book|last=Renz|first=Mark|title=Megalodon: Hunting the Hunter|pages=26–30|publisher=PaleoPress|year=2002|isbn=0-9719477-0-8}} However, as is the case with O. megalodon, the classification of this species is disputed.

Taxonomy

As is the case with other known megatoothed sharks, the genus of O. chubutensis remains in dispute.{{Cite journal|author1=Gottfried M.D. |author2=Fordyce R.E |title=An Associated Specimen of CARCHARODON ANGUSTIDENS (CHONDRICHTHYES, LAMNIDAE) From the LATE OLIGOCENE of NEW ZEALAND, with comments on CARCHARODON Interrelationships|year=2001|journal=Journal of Vertebrate Paleontology|volume =21|issue=4|pages=730–739|doi=10.1671/0272-4634(2001)021[0730:AASOCA]2.0.CO;2|s2cid=86092645 |issn=0272-4634}} The Swiss naturalist Louis Agassiz first identified this shark as a species of Carcharodon in 1843.{{Cite book |last1=Klimley |first1=Peter |url=https://archive.org/details/greatwhitesharkb0000unse |title=Great White Sharks: The Biology of Carcharodon carcharias |last2=Ainley |first2=David |publisher=Academic Press |year=1996 |isbn=0-12-415031-4 |page=[https://archive.org/details/greatwhitesharkb0000unse/page/31 31] |url-access=limited}} In 1906, Ameghino renamed this shark as Carcharodon chubutensis.{{Cite web|last=Andres|first=Lutz|title=Megatooth Fossils Found at the Calvert Cliffs of Maryland|url=http://www.fossilguy.com/sites/calvert/calv_meg.htm|archive-url=https://web.archive.org/web/20220826104122/http://www.fossilguy.com/sites/calvert/calv_meg.htm|archive-date=26 August 2022|accessdate=10 September 2022}} In 1964, shark researcher, L. S. Glikman recognized the transition of Otodus obliquus to O. auriculatus. In 1987, shark researcher, H. Cappetta reorganized the O. auriculatus - O. megalodon lineage and placed all related megatoothed sharks along with this species in the genus Carcharocles ( now Otodus).{{Cite journal |last=Shimada |first=Kenshu |last2=Chandler |first2=Richard E. |last3=Lam |first3=Otto Lok Tao |last4=Tanaka |first4=Takeshi |last5=Ward |first5=David J. |date=2017-07-04 |title=A new elusive otodontid shark (Lamniformes: Otodontidae) from the lower Miocene, and comments on the taxonomy of otodontid genera, including the ‘megatoothed’ clade |url=https://www.tandfonline.com/doi/full/10.1080/08912963.2016.1236795 |journal=Historical Biology |language=en |volume=29 |issue=5 |pages=704–714 |doi=10.1080/08912963.2016.1236795 |issn=0891-2963|url-access=subscription }} Finally, the complete Otodus obliquus to O. megalodon progression became clear and has since gained the acceptance of many shark researchers.{{Cite web|last=Andres|first=Lutz|title=C. megalodon — Megatooth Shark, Carcharodon versus Carcharocles|url=http://www.fossilguy.com/topics/megshark/megshark.htm|year=2002|accessdate=2010-05-10}}

Within the Otodus lineage; O. chubutensis is the succeeding species of O. angustidens and is followed by O. megalodon. In short, O. chubutensis is considered a possible ancestor of O. megalodon.{{Cite news|last=Bruner|first=John|title=The "Megatooth" shark, Carcharodon megalodon|year=1997|publisher=Mundo Marino Revista Internacional de Vida Marina}} However, due to its co-existence with O. megalodon during the Miocene and Pliocene epochs, it is regarded as a morpho-species.

Size

Otodus chubutensis was a large lamniform shark, with the largest individuals reaching a body length of {{convert|13.5|m|ft}}.{{cite journal |last1=Kast |first1=Emma R. |last2=Griffiths |first2=Michael L. |last3=Kim |first3=Sora. L. |last4=Rao |first4=Zixuan C. |last5=Shimada |first5=Kensu |last6=Becker |first6=Martin A. |last7=Maisch |first7=Harry M. |last8=Eagle |first8=Robert A. |last9=Clarke |first9=Chelesia A. |last10=Neumann |first10=Allison N. |last11=Karnes |first11=Molly E. |last12=Lüdecke |first12=Tina |last13=Leichliter |first13=Jennifer N. |last14=Martínez-García |first14=Alfredo |last15=Akhtar |first15=Alliya A. |last16=Wang |first16=Xingchen T. |last17=Haug |first17=Gerald H. |last18=Sigman |first18=Daniel M. |date=22 June 2022 |title=Cenozoic megatooth sharks occupied extremely high trophic positions |journal=Science Advances |volume=8 |issue=25 |at=eabl6529 |doi=10.1126/sciadv.abl6529 |pmid=35731884 |pmc=9217088 |bibcode=2022SciA....8L6529K}} Relatively large individuals reached body lengths of {{convert|9|-|11|m|ft}}.{{Cite journal |last1=Perez |first1=Victor |last2=Leder |first2=Ronny |last3=Badaut |first3=Teddy |date=2021 |title=Body length estimation of Neogene macrophagous lamniform sharks (Carcharodon and Otodus) derived from associated fossil dentitions |url=https://palaeo-electronica.org/content/2021/3284-estimating-lamniform-body-size |journal=Palaeontologia Electronica |volume=24 |issue=1 |pages=1–28 |doi=10.26879/1140 |doi-access=free}} Smaller individuals were still about the size of the modern great white shark, reaching body lengths of {{convert|4.6|-|6.3|m|ft}}.{{Cite journal |last1=McCormack |first1=Jeremy |last2=Griffiths |first2=Michael L. |last3=Kim |first3=Sora L. |last4=Shimada |first4=Kenshu |last5=Karnes |first5=Molly |last6=Maisch |first6=Harry |last7=Pederzani |first7=Sarah |last8=Bourgon |first8=Nicolas |last9=Jaouen |first9=Klervia |last10=Becker |first10=Martin A. |last11=Jöns |first11=Niels |date=31 May 2022 |title=Trophic position of Otodus megalodon and great white sharks through time revealed by zinc isotopes |journal=Nature Communications |language=en |volume=13 |issue=1 |pages=2980 |doi=10.1038/s41467-022-30528-9 |pmid=35641494 |pmc=9156768 |bibcode=2022NatCo..13.2980M |s2cid=249235478 |issn=2041-1723}}

Paleoecology

Paleontological research suggests that this species may have changed habitat preferences through time, or it may have had enough behavioral flexibility to occupy different environments at different times.

= Diet =

Otodus chubutensis was likely an apex predator and commonly preyed upon fish, sea turtles, cetaceans (e.g. whales), and sirenids.

There is also potential evidence that Otodus hunted raptorial sperm whales; a tooth belonging to an undetermined {{convert|4|m|ft|abbr=on}} physeteroid closely resembling those of Acrophyseter discovered in the Nutrien Aurora Phosphate Mine in North Carolina suggests that a megalodon or O. chubutensis may have aimed for the head of the sperm whale in order to inflict a fatal bite, the resulting attack leaving distinctive bite marks on the tooth. While scavenging behavior cannot be ruled out as a possibility, the placement of the bite marks is more consistent with predatory attacks than feeding by scavenging, as the jaw is not a particularly nutritious area to for a shark feed or focus on. The fact that the bite marks were found on the tooth's roots further suggest that the shark broke the whale's jaw during the bite, suggesting the bite was extremely powerful. The fossil is also notable as it stands as the first known instance of an antagonistic interaction between a sperm whale and an otodontid shark recorded in the fossil record.{{Cite journal |last1= Godfrey |first1=Stephen J. |last2= Nance |first2=John R. |last3=Riker |first3=Norman L. |date=2021 |title=Otodus-bitten sperm whale tooth from the Neogene of the Coastal Eastern United States |url=http://app.pan.pl/archive/published/app66/app008202020.pdf |journal=Acta Palaeontologica Polonica |volume=66 |issue=3 |pages=599–603|doi=10.4202/app.00820.2020 }}

Fossil record

This species is also known from fossil teeth and some fossilized vertebral centra. Shark skeletons are composed of cartilage and not bone, and cartilage rarely gets fossilized. Hence, fossils of O. chubutensis are generally poorly preserved. Although the teeth of O. chubutensis are morphologically similar to teeth of O. megalodon,{{Cite journal|author1=Nyberg K.G |author2=Ciampaglio C.N |author3=Wray G.A |title=Tracing the ancestry of the GREAT WHITE SHARK|year=2006|journal=Journal of Vertebrate Paleontology|volume=26|issue=4|pages=806–814|doi=10.1671/0272-4634(2006)26[806:TTAOTG]2.0.CO;2|s2cid=53640614 |issn=0272-4634}} they are comparatively slender with curved crown, and with presence of lateral heels feebly serrated.{{Cite journal |last1=Aguilera |first1=O. |last2=Augilera |first2=E. R. D. |year=2004 |title=Giant-toothed White Sharks and Wide-toothed Mako (Lamnidae) from the Venezuela Neogene: Their Role in the Caribbean, Shallow-water Fish Assemblage |url=https://app.ingemmet.gob.pe/biblioteca/pdf/Paleo-56.pdf |journal=Caribbean Journal of Science |volume=40 |issue=3 |pages=362–368}} Fossils of this species have been found in North America, South America, Africa,{{Cite journal|last=Cook|first=Todd D.|author2=Alison M. Murray |author3=Elwyn L. Simons |author4=Yousry S. Attia |author5=Prithijit Chatrath |title=A Miocene selachian fauna from Moghra, Egypt|journal=Historical Biology|location=Egypt|date=18 February 2010|doi=10.1080/08912960903249329|volume=22|issue=1–3|pages=78–87|bibcode=2010HBio...22...78C |s2cid=128469722 }} and Europe.{{Cite journal|last=Marsili|first=Stefano|author2=Giorgio Carnevale |author3=Ermanno Danesea |author4=Giovanni Bianuccia |author5=Walter Landinia |title=Early Miocene vertebrates from Montagna della Maiella, Italy|journal=Annales de Paléontologie|volume=93|issue=1|pages=27–66|publisher=Elsevier|location=Italy| date=March 2007|doi=10.1016/j.annpal.2007.01.001|bibcode=2007AnPal..93...27M }} Its fossils have also been discovered in Asia and Australia.{{cite journal|author1=Harry M. Maisch, IV|author2=Martin A. Becker|author3=John A. Chamberlain, Jr.|year=2018|title=Lamniform and Carcharhiniform Sharks from the Pungo River and Yorktown Formations (Miocene–Pliocene) of the Submerged Continental Shelf, Onslow Bay, North Carolina, USA|journal=Copeia|volume=106|issue=2|pages=353–374|doi=10.1643/OT-18-016|s2cid=91348616 }}

= Locations =

;South America[https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=301191 Otodus chubutensis] at Fossilworks.org

Pisco Formation and Chilcatay Formation, Peru
Pirabas Formation, Brazil
Jimol Formation, Colombia
Cantaure Formation, Venezuela

;North America

Culebra Formation, Panama
Arcadia Formation, Florida
Pungo River Formation, North Carolina
Calvert Formation, Delaware

;Europe

Bolognano Formation, Italy

References

External links

[http://www.elasmo.com/frameMe.html?file=genera/cenozoic/sharks/carcharocles.html&menu=bin/menu_genera-alt.html Carcharocles: Extinct Megatoothed shark] from ELASMO
[http://www.fossilguy.com/gallery/vert/fish-shark/carcharocles/carcharocles.htm Megatooth Shark Information - Facts, Evolution, Extinction, Fossil Examples] from Fossilguy.com

chubutensis

Category:Oligocene sharks

Category:Miocene sharks

Category:Pliocene sharks

Category:Prehistoric fish of Africa

Category:Fossils of Egypt

Category:Prehistoric fish of Europe

Category:Fossils of Italy

Category:Paleogene fish of North America

Category:Neogene fish of North America

Category:Prehistoric fish of South America

Category:Paleogene animals of South America