Extinct 'megamouth' Shark Species Finally Identified

[John Hamilton]

http://news.yahoo.com/extinct-megamouth-shark-species-finally-identified-153514600.html

[Auspex]

Progress!

[fossilselachian]

http://news.yahoo.com/extinct-megamouth-shark-species-finally-identified-153514600.html

I was fortunate to acquire two of these teeth at least 15 years ago from Bruce Welton when he made his one visit to the MAPS Expo. A few others were obtained in later years from a well known TFF member who, at least at the time, had a "stash" of such teeth also acquired from Welton.

It's good to hear the shark has been described and (soon) will have an official genus/species name.

[mrieder79]

The article mentioned that the teeth were found in deep sea sediment, among other places. I am assuming this refers to sediment that, millions of years ago, was deep sea and not that the find was made in the deep sea today. Thoughts?

[Auspex]

The article mentioned that the teeth were found in deep sea sediment, among other places. I am assuming this refers to sediment that, millions of years ago, was deep sea...

This is correct. Being found in sediments laid down in deep water, as well as those from shallow water deposits, is why they propose that the shark, at times, inhabited both environments.

[siteseer]

I just found this thread after running across the article as a link to the new one on Bandringa. I was going to start a thread for it but went back to see if someone else had already started one.

Yes, at least one of the "megamouth" sites is an exposure of the Early Miocene age Skooner Gulch Formation (Mendocino County, California) which has been interpreted as representing a "middle bathyal environment," (see Phillips, et al,. 1976) in other words an ocean bottom area. Most deepwater-representing sites are still in deepwater but the Skooner Gulch site is in a beach area - the result of a lower sea level than during the Early Miocene combined with perhaps some local uplift.

The Early Miocene teeth are also known from the Freeman Silt and the Pyramid Hill Sand Member of the Jewett Sand. The latter is known to contain both shallow and deepwater sharks.

These teeth were first noted in an informally-published article based on lecture notes (Bishop, 1961) and identified as "Odontaspis sp. 1" (fig. 21). The teeth are also briefly discussed, figured, but not officially described by Stewart in Lavenberg (1991:p. 34).

I learned about these teeth over twenty years ago and assumed Bruce Welton would get around to describing them at some point especially after the passing of Shelton Applegate who along with Richard C. Bishop was among the first to recognize the teeth as unusual. Since the 90's various researchers have considered describing the form. Anteriors, laterals, and apparent posteriors had been informally recognized so a composite dentition may be revealed in the paper (perhaps assembled as early as the 1980's after the discovery of the modern megamouth in 1976 though researchers at the time considered the possibility that it was an unrelated form with similar teeth). However, it became understood that Welton sort of had that "claim." already even though decades have passed since the initial discovery.

I hope the species name honors one of the collectors/researchers from the 50's or 60's or at least mentions some of them though many have since passed away. I certainly look forward to reading the official description after my own comparatively short wait.

Bishop, R.C. 1961.

Shark's Teeth from the Temblor Basin.near Bakersfield, California. Taft Westside Gemstone and Mineral Society, Inc.

Lavenberg, R. 1991.

Megamania: The Continuing Saga of Megamouth Sharks. Terra. 30(1):30-39. Fall 1991.

Phillips, F.J,, B.Welton, and J. Welton. 1976..

Paleontologic Studies of the Middle Tertiary Skooner Gulch and Galloway Formations at Point Arena, California. In Fritsche, A.E., H.T. Best, Jr., and W.W. Wornardt (eds.). The Neogene Symposium: selected papers on paleontology, sedimentology, petrology, tectonics, geologic history of the Pacific Coast of North America.. Annual Meeting Pacific Section SEPM San Francisco, California. April 1976. pp.137-154.

The article mentioned that the teeth were found in deep sea sediment, among other places. I am assuming this refers to sediment that, millions of years ago, was deep sea and not that the find was made in the deep sea today. Thoughts?

Edited January 8, 2014 by siteseer