using teeth to determine the evolutionary lineage of the great white shark sarah elise field bailey...

Using Teeth to Determine the Evolutionary Lineage of

the Great White Shark

Sarah Elise Field Bailey Keeler Elizabeth Lillard Kristin Oliver

Relating to Our Lectures:Craniate Relationships

Chondrichthyes

Osteichthyes

Sarcopterygii

Actinopterygii

Vertebrates

CRAN

IATE

S

Why Study Shark Tooth

Evolution?

• Sharks are cartilaginous • Teeth are calcified – long lasting• Good for pre-historic shark

morphology, predation techniques, and environmental conditions.

• Common ancestor with bony fishes: feeding behaviors can shed light on vertebrate feeding systems function and evolution. (Motta 2001, 132)

Examples of Extinct Mako Teeth

• Sharp, needle like teeth usually indicate a diet consisting primarily of fish. Pointy teeth are good for catching streamlined-slippery prey.

• -elasmo-research.org (Images) -Shark Savers (text)

Shortfin Mako Tooth

• A modern day Mako tooth.

Megalodon Tooth

-Broadly Triangular, thick, with fine serrations.

-ReefQuest

Otodus Obliquus

• A direct descendent of the Megalodon (Carcharocles megalodon). A more triangular smooth blade.

• ReefQuest

Great White Shark (Carcharodon carcharias)

Broadly triangular, flattened, coarsely serrated. –ReefQuest

Teeth Through the Ages

Other Shark Teeth Morphologies

• There are also benthic feeding sharks with plate-like teeth for crushing the shells of their prey, and filter feeders like the whale shark whose teeth are tiny and useless. (Shark Savers)

Australianmuseum.net

MEGALODON

Megalodon

Megalodon-Great White Theory (pros)• Tooth morphology

– size and shape– Linnaean System (Early 1800’s)

• Heterochrony– Size and shape are a result of

differences in the timing of development • Vertebras

– similar

Discrepancies

(Ciampaglio)

(Megalodon)

(Great White)

(Ancestral Mako)

Carcharodon carcharias

http://www.badhaven.com/special-features/great-white-shark-origins-debunked-with-new-fossil-evidence/

Carcharodon hastalis

Carcharodon hubbelli at the Pisco Formation

Carcharodon hubbelli

C. hubbelli Vertebrae

Other Examples of Shark Teeth

Lemon Shark Bull Shark

Tiger SharkNurse Shark

Whale Shark

???????????

Helicoprion!

Early Theories

Shift to Lower Jaw

Most Current Theory

Frill Shark!

X 25 rows

Conservation

Conservation: Studying shark teeth sheds light on feeding strategy and environmental

conditions which would allow conservationists to make more informed decisions

regarding the ecosystems and prey necessary to sustain a population of

Great Whites. Also, understanding their

evolution could shed light on the possible adaptive

strategies utilized by sharks in response to changing

environments.

Further Research

Any Questions?

Citations• Castro, J. I. Great white sharks: The biology of carcharodon carcharias. 1998.

Ciampaglio, C. N., & Wray, G. A. Tracing the ancestry of the great white shark, carcharodon carcharias, using morphometric analyses of fossil teeth. 2006. Journal of Vertebrate Paleontology, 26(4): 806.

Ebert, D., and L. Compagno. Chlamydoselachus Africana, a New Species of Frilled Shark from Southern Africa. 2009. Zootaxa 2173: n. pag. Web.

Ehret, Dana J. Origin of the White Shark Carcharodon (Lamniformes: Lamnidae) Based on Recalibration of the Upper Neogene Pisco Formation of Peru. 2012. Palaeontology 55.6: 1139-153. The Palaeontological Association. Web. 19 Nov. 2012.

Lebedev, O. A New Specimen of Helicoprion Karpinsky , 1899 from Kazakhstanian Cisurals and a New Reconstruction of Its Tooth Whorl and Function. 2009. Acta Zoologica 90: 171-82. Web.

Manning, P. Giant shark: Megalodon, prehistoric super predator. 2000. New York: Media Source.

Martin, A. Deep Sea: Frilled Shark. Deep Sea: Frilled Shark. 2003. N.p., Web. <http://elasmo-research.org/education/ecology/deepsea-frilled_shark.htm>.

Motta, Philip J., and Cheryl D. Wilga. Advances in the Study of Feeding Behaviors, Mechanisms, and Mechanics of Sharks. 2001. Environmental Biology of Fishes 60: 131-56.

Paul, L. & Fowler, S. (SSG Australia & Oceania Regional Workshop, March 2003) 2003. Chlamydoselachus anguineus. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>

Purdy, R. The Orthodonty of Helicoprion. Smithsonian Department of Paleobiology, 2008. Web.

ReefQuest Center for Shark Research. Lamniformes: Mackerel Sharks. Web. 23 Nov. 2012. <http://www.elasmo-research.org/education/shark_profiles/lamniformes.htm>.

Renz, Mark. Megalodon: Hunting the Hunter. 2002. PaleoPress.

Shark Savers Inc. Shark Teeth. Web. 22 Nov. 2012. <http://www.sharksavers.org/en/education/biology/shark-teeth1/>.

Tanaka, S., Y. Shiobara, S. Hioki, H. Abe, G. Nishi, K. Yano, and K. Suzuki. The Reproductive Biology of the Frilled Shark, Chlamydoselachus Anguineus from Suruga Bay, Japan. 1990. Japanese Journal of Ichthyology 37.3: n. pag. Web

Venice Florida dot com!. Venice Florida- Shark and Sharks’ Teeth Information. Shark Teeth-General Info. Web. 22 Nov. 2012. <http://www.veniceflorida.com/shark.htm>.