Carcharodon hubbelli
Holotype jaws and teeth (UF 226255), also known as the Sacaco specimen
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Subdivision: Selachimorpha
Order: Lamniformes
Family: Lamnidae
Genus: Carcharodon
Species:
†C. hubbelli
Binomial name
†Carcharodon hubbelli
Ehret et al., 2012

Carcharodon hubbelli, also known as Hubbell's white shark, is an extinct species of white shark that evolved between 8 and 5 million years ago during the Late Miocene to Early Pliocene epochs. This shark is a transitional species, showing intermediate features between the extant great white shark and the fossil white shark, Carcharodon hastalis.[2][3][4] C. hubbelli appears to be geographically restricted to the Pacific Ocean, with fossils of C. hubbelli recovered from Peru,[4] Chile, California,[5] and New Zealand.[6] This exclusive distribution suggests a Pacific origin for the great white shark.

This shark was named in honor of Dr. Gordon Hubbell (the scientist who recovered the specimen from a farmer who found it in 1988)[7] in recognition of his contribution to shark paleontology and for donating the specimen to the Florida Museum of Natural History in 2009.[8][3][9] It was about the size of the modern great white shark, reaching 4.9–5.1 metres (16–17 ft) long.[3][10] Its growth curve shows that it grew at a slower rate than the modern great white shark.[3]

Dentition

Only one associated dentition of C. hubbelli is known (UF 226255), with a total of 222 teeth (and 45 vertebral centra). It was recovered from the Pisco Formation of Southern Peru. The tooth morphology is most similar to the extant great white, in having labiolingually flattened triangular cusps with serrated edges. The dentition differs from the extant species in having a distally-inclined upper intermediate tooth (it is mesially-inclined in the great white). The serrations are also qualitatively different, being finer and diminish in size apically (towards the tip).[11]

Functional tooth set of C. hubbelli. Scale bar is 5 cm.

As a transitional species, C. hubbelli possesses a mixture of features present in extinct white sharks like C. hastalis and in the extant white shark, C. carcharias. The distal inclination of the intermediate tooth is characteristic of C. hastalis, but the presence of serrations (though not fully developed) and a second upper anterior tooth larger than the lower second anterior tooth are characteristic of C. carcharias.[11]

Transition of C. hubbelli



Ecology

The development of serrated edges on the teeth of C. hubbelli suggest a shift in its diet to rely more on marine mammals as in C. carcharias. The bone of a scavenged mysticete whale with a tooth of C. hubbelli embedded within it supports this hypothesis.[12]

References

  1. ↑ Boessenecker, R. W.; Ehret, D. J.; Long, D. J.; Churchill, M.; Martin, E.; Boessenecker, S. J. (2019). "The Early Pliocene extinction of the mega-toothed shark Otodus megalodon: a view from the eastern North Pacific". PeerJ. 7: e6088. doi:10.7717/peerj.6088. PMC 6377595. PMID 30783558.
  2. ↑ Nick Crumpton (14 November 2012). "Great whites not evolved from megashark'". BBC. Retrieved 14 November 2012.
  3. 1 2 3 4 Dana J. Ehret; Bruce J. Macfadden; Douglas S. Jones; Thomas J. Devries; David A. Foster; Rodolfo Salas-Gismondi (2012). "Origin of the white shark Carcharodon (Lamniformes: Lamnidae) based on recalibration of the Upper Neogene Pisco Formation of Peru". Palaeontology. 55 (6): 1139–1153. Bibcode:2012Palgy..55.1139E. doi:10.1111/j.1475-4983.2012.01201.x. S2CID 128666594.
  4. 1 2 Ehret, Dana J.; Hubbell, Gordon; Macfadden, Bruce J. (2009). "Exceptional preservation of the white shark Carcharodon (Lamniformes, Lamnidae) from the early Pliocene of Peru". Journal of Vertebrate Paleontology. 29 (1): 1–13. Bibcode:2009JVPal..29....1E. doi:10.1671/039.029.0113. S2CID 129585445. Retrieved 1 December 2020.
  5. ↑ Boessenecker, Robert W. 2016. First record of the megatoothed shark Carcharocles megalodon from the Mio-Pliocene Purisima Forma-tion of Northern California. PaleoBios, 33. ucmp_paleobios_32076
  6. ↑ Torrent, Danielle (4 November 2012). "New ancient shark species gives insight into origin of great white". Florida Museum of Natural History. University of Florida. Retrieved 4 November 2012.
  7. ↑ "New ancient shark species gives insight into origin of great white". University of Florida News. 2012-11-14. Archived from the original on 2013-03-07. Retrieved 2013-03-28.
  8. ↑ de Lazaro, Enrico. "Study: White Shark May Have Evolved from Mako Shark". Sci-News.com. Retrieved 15 November 2012.
  9. ↑ Torrent, Danielle (4 November 2012). "New ancient shark species gives insight into origin of great white". Florida Museum of Natural History. University of Florida. Retrieved 4 November 2012.
  10. ↑ Perez, Victor; Leder, Ronny; Badaut, Teddy (2021). "Body length estimation of Neogene macrophagous lamniform sharks (Carcharodon and Otodus) derived from associated fossil dentitions". Palaeontologia Electronica. 24 (1): 1–28. doi:10.26879/1140.
  11. 1 2 Ehret, D.J., Macfadden, B.J., Jones, D.S., DeVries, T.J., Foster, D.A. and Salas-Gismondi, R. (2012), Origin of the white shark Carcharodon (Lamniformes: Lamnidae) based on recalibration of the Upper Neogene Pisco Formation of Peru. Palaeontology, 55: 1139-1153. doi:10.1111/j.1475-4983.2012.01201.x
  12. ↑ Dana J. Ehret, Bruce J. MacFadden, Rodolfo Salas-Gismondi (2009), "Caught in the act: Trophic interactions between a 4-million-year-old white shark (Carcharodon) and mysticete whale from Peru," Palaios, 24(5), 329-333.
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