Materpiscis

Scientific classification

Kingdom: Animalia

Phylum: Chordata

Subphylum: Vertebrata

Class: Placodermi

Infraclass: Tetrapodomorpha

Order: Ptyctoodntida

Family: Ptyctodontidae

Genus: Materpiscis Long et al. 2008

Species: M. attenboroughi Long et al. 2008

Materpiscis

Materpiscis (from the Latin meaning ‘mother fish’) is a genus of ptyctodotid placoderm from the Late Devonian (c. 380 million years old) Gogo Formation of Western Australia, described by John Long of Museum Victoria and colleagues. IT was about 25-30 cm long and had powerful crushing tooth plates to grind up its prey, possibly hard shelled invertebrates like clams or corals. Known from only one specimen, it is unique in having an unborn embryo present inside the mother fish, and with remarkable preservation of a mineralised placental feeding structure (umbilical cord). This make Materpiscis the oldest known vertebrate to show viviparity , or giving birth to live young. The species name, M. attenboroughi honours Sir David Attenborough who first drew attention to the significance of the Gogo fish sites in his 1979 series “Life on Earth” (episode 4).

The ptyctodontid fishes are the only group of placoderms to display sexual dimorphism, where males have clasping organs and females have smooth pelvic fin bases. It had long been suspected that they reproduced using internal fertilisation, but finding fossilised embryos inside both Materpiscis and in a similar form also from Gogo, Austroptyctodus, proved the inference was true.

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See also

Other fish found in fossils from the Devonian period:

Tiktaalik

Eusthenopteron

Panderichthys

Coelacanthimorpha

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References

Long, J. A., 1985, "A new osteolepidid fish from the Upper Devonian Gogo Formation of Western Australia", Recs. W. A. Mus. 12, 361–377.

Long, J. A. 1988, Late Devonian fishes from Gogo, Western Australia. Nat. Geog Research & Exploration 4: 436-450. Long, J. A. et al., 1997, "Osteology and functional morphology of the osteolepiform fish Gogonasus Long, 1985, from the Upper Devonian Gogo Formation, Western Australia", Recs. W. A. Mus. Suppl. 57, 1–89

Long, J. A. et al., 2006, "An exceptional Devonian fish from Australia sheds light on tetrapod origins", Nature 444, 199-202

Long, J. A. 2006. "Swimming in Stone -the amazing Gogo fossils of the Kimberley" Fremantle Arts Centre Press, Fremantle. 320pp. ISBN 1-921064-33-1

Rosen, D. E., Forey, P.L., Gardiner, B.G. & Patterson, C. 1981, Lungfishes, tetrapods, paleontology and plesiomorphy. Bull. Am. musm. Nat. Hist. 167 (4): 159-276.

Long, J.A., Trinajstic, K., Young, G.C. & Sende, T. 2008. Live birth in the Devonian period. Nature 453: 650-652

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External links

Ancient Gogonasus advances evolution, Museum Victoria.[1]

Photographs and x-ray micro-tomography animation of Gogonasus from ANU [2]

Gogonasus andrewsae by PZ Myers

Ancient Fish Fossil May Rewrite Story of Animal Evolution (National Geographic)

Livescience.com: "Discovery Points to Our Fishy Heritage." (Accessed 10/21/06)

Fox News: Primitive Fish Skeleton May Link Land, Sea Interview with Dr John Long, curator at the Museum of Victoria