jerseydigger Posted November 26, 2012 Share Posted November 26, 2012 Sorry for the silly question, but are trilobites an early form of horseshoe crab, or in the crab family? And also what are the largest one's avg. size? Most I have seen are about an inch to three inches. Thanks from a newbie! Link to comment Share on other sites More sharing options...
Northern Sharks Posted November 26, 2012 Share Posted November 26, 2012 Trilobites are arthropods and distantly related to crabs. This has also been talked about recently in another thread. The largest so far is Isotelus rex which measures 720mm or about 28" long. The smallest adult species are only a few mm long There's no limit to what you can accomplish when you're supposed to be doing something else Link to comment Share on other sites More sharing options...
piranha Posted November 26, 2012 Share Posted November 26, 2012 Trilobites and horseshoe crabs are in the same Superclass: Arachnomorpha. However, within that group they are split and only distantly related. The first trilobites appear in the lower Cambrian at 525 Mya and the first horseshoe crabs in the upper Ordovician at 445 Mya. Horseshoe crabs are classified as Chelicerata and not actually crustaceans and trilobites are designated within a separate and unique Class: Trilobita. You can find many excellent open-access articles on these topics searching Google Scholar or Wikipedia. There are several large trilobite genera that approach or exceed a foot in length. Isotelus rex from Manitoba is the largest recorded trilobite at 70 cm (28 inches) LINK Link to comment Share on other sites More sharing options...
jerseydigger Posted November 26, 2012 Author Share Posted November 26, 2012 you guys are awesome! Thank you! Link to comment Share on other sites More sharing options...
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