Prehistoric Life/Other Extinct Creatures: Difference between revisions
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For obvious reason, our curiosity now reaches the top: which were the first animals (not counting protozoans) that thrived in our oceans? Well, the answer is not simple: we can divide them in two ensembles. One is made from those groups either still alive today or extinct several ages after the Cambrian: among the former, most non-arthropod / non-cephalopod invertebrate groups already seen; among the latter, the Trilobites. We'll talk here about the second ensemble: many Cambrian invertebrates were indeed ''exclusive of the Cambrian'' and didn't survive long enough, not even to reach the following period, Ordovician--in which the most famous Paleozoic critters, sea-scorpions, nautiloids, armored fish etc. appeared. Thus, is easy to imagine many of them were ''really'' [[Our Monsters Are Weird|bizarre-looking]] to our limited point of view. We still know very very few things about their lifestyle, but their appearence is extraordinarily well-known, because these Cambrian deposits ''have preserved soft-bodies''; not only that, they have preserved them very well! |
For obvious reason, our curiosity now reaches the top: which were the first animals (not counting protozoans) that thrived in our oceans? Well, the answer is not simple: we can divide them in two ensembles. One is made from those groups either still alive today or extinct several ages after the Cambrian: among the former, most non-arthropod / non-cephalopod invertebrate groups already seen; among the latter, the Trilobites. We'll talk here about the second ensemble: many Cambrian invertebrates were indeed ''exclusive of the Cambrian'' and didn't survive long enough, not even to reach the following period, Ordovician--in which the most famous Paleozoic critters, sea-scorpions, nautiloids, armored fish etc. appeared. Thus, is easy to imagine many of them were ''really'' [[Our Monsters Are Weird|bizarre-looking]] to our limited point of view. We still know very very few things about their lifestyle, but their appearence is extraordinarily well-known, because these Cambrian deposits ''have preserved soft-bodies''; not only that, they have preserved them very well! |
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It would be too long to mention [http://en.wikipedia.org/wiki/Burgess_Shale_type_fauna all the members] of the Cambrian Fauna: see |
It would be too long to mention [http://en.wikipedia.org/wiki/Burgess_Shale_type_fauna all the members] of the Cambrian Fauna: see [http://www.google.it/imgres?imgurl=http://www.trilobites.info/burgess_community_sm.jpg&imgrefurl=http://www.trilobites.info/triloclass.htm&usg=__s0Eofooa0oLw4onLe4Slh3sbJ6g=&h=479&w=720&sz=125&hl=it&start=10&zoom=1&um=1&itbs=1&tbnid=3LpTQO2S2iy5RM:&tbnh=93&tbnw=140&prev=/images%3Fq%3Dcambrian%2Bfauna%26um%3D1%26hl%3Dit%26rls%3Dcom.microsoft:en-US%26rlz%3D1I7ADBF_it%26tbs%3Disch:1&ei=lyRVTZfKAcTrOYLpxYAF the image here] for having an idea. It's immediately recognizable the bizarre shrimp-like animal in the center, by far the biggest creature in this fauna, and arguably the top predator. It is called ''[http://en.wikipedia.org/wiki/Anomalocaris Anomalocaris]'' (meaning "[[Exactly What It Says On the Tin|bizarre shrimp]]" indeed), and was a distant relative of arthropods with no articulated legs but with the same composed eyes of the Trilobites. Of course it is the most portrayed Cambrian animal in documentaries and illustrations, classicaly mentioned as "[[Prehistoric Monster|the first prehistoric monster ever appeared on Earth]]". Actually, if alive today, the "terrible" anomalocarid would appear as a really [[Narm|narmy thing]], a sort of 3 ft long, shell-less, pincer-less lobster, nothing dangerous for a tough-boned, tough-muscled, tough-skinned mammal we are in comparison. Nonetheless, anomalocarids were highly specialized predators, with a mouth build for prey around 1/12 to 1/6 of their own size. |
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However, at the anomalocaris’ time, every other organism was ''very small'': The other creatures you see in the linked image are not longer than your hand, all possible prey for anomalocarids. <ref> Except those which were so small that a full grown ''Anomalocaris canadensis'' (the largest know species) whould have ignored them</ref>. Creatures like ''Hallucigenia'' and ''Pikaia'' were hunted by smaller predators, such as ''Opabinia'' and ''Anomalocaris saron''. The later was the species shown in ''[[Walking With Monsters]]'', though ridiculously oversized (6 ft.!?) and prone to attack it's own kind, despite the fact that neither its mouth nor grasps could injur an equally sized specimen in the way it was depicted, let alone possibly eating it. |
However, at the anomalocaris’ time, every other organism was ''very small'': The other creatures you see in the linked image are not longer than your hand, all possible prey for anomalocarids. <ref> Except those which were so small that a full grown ''Anomalocaris canadensis'' (the largest know species) whould have ignored them</ref>. Creatures like ''Hallucigenia'' and ''Pikaia'' were hunted by smaller predators, such as ''Opabinia'' and ''Anomalocaris saron''. The later was the species shown in ''[[Walking With Monsters]]'', though ridiculously oversized (6 ft.!?) and prone to attack it's own kind, despite the fact that neither its mouth nor grasps could injur an equally sized specimen in the way it was depicted, let alone possibly eating it. |
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[[Category:Tropesaurus Index]] |
[[Category:Tropesaurus Index]] |
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[[Category:Prehistoric Life Other Extinct Creatures]] |
[[Category:Prehistoric Life Other Extinct Creatures]] |
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[[Category:Useful Notes |
[[Category:Useful Notes]] |
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