Ancient Sharks in Nebraska

Curt Bright Author

07/13/2018 Added

1875 Plays

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Nebraska was once beneath a shallow sea teaming with life including early sharks.

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[00:00:00.421](dramatic shark music)
[00:00:03.052](crunching)
[00:00:05.870]Nebraska is basically built
[00:00:08.130]on top of ancient marine sediments
[00:00:10.600]that have been lithified into sedimentary rocks,
[00:00:13.250]so essentially all of Nebraska
[00:00:15.940]is under layen by marine sedimentary rocks
[00:00:19.150]meaning that the entire state
[00:00:20.960]at one time or another in geologic history
[00:00:24.247]was inundated by shallow seas.
[00:00:27.804](water whooshes)
[00:00:31.200]By shallow we're talking about 100s of meters in depth
[00:00:35.350]rather than true oceanic depths.
[00:00:39.261]The first true sharks or something remotely like true sharks
[00:00:43.930]appeared between about 400 and 450 million years ago.
[00:00:49.000]This animal called Petalodus
[00:00:52.000]and this other one called Edestus are very old sharks
[00:00:56.150]that we might find remains of
[00:00:58.630]in Nebraska from about 300 million years ago,
[00:01:02.520]not closely related to modern sharks at all
[00:01:05.620]but they both had really sharp teeth
[00:01:07.890]and they both could have probably done some damage to you
[00:01:10.590]if they'd caught you out swimming
[00:01:12.400]in those 300-million-year-oceans.
[00:01:14.764](dramatic shark music)
[00:01:17.870]Now, we'll contrast that with this fellow down here
[00:01:21.810]which reached lengths of 33 feet
[00:01:25.110]or perhaps even more.
[00:01:26.860]This shark was called Ptychodus
[00:01:29.620]and you would have encountered him
[00:01:31.050]certainly in those cretaceous shallow seas,
[00:01:34.960]perhaps around 90 to 70 million years ago in Nebraska.
[00:01:41.004](water whooshes)
[00:01:43.490]Its teeth are quite different.
[00:01:45.430]They look like the rounded peen on a ball-peen hammer.
[00:01:49.720]So, a crunching-tooth shark
[00:01:51.600]that probably ate clams and such
[00:01:54.800]and two much older shark-like fish
[00:01:57.520]that certainly preyed upon other animals
[00:02:00.690]including other fish and had nice sharp teeth.
[00:02:03.650]Any way you slice it
[00:02:04.870]from ancient seas to ancient plains, ancient rivers,
[00:02:10.650]all kinds of interesting geologic phenomena
[00:02:14.210]in Nebraska's past.
[00:02:16.119](lively music)

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Ancient Sharks in Nebraska

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