Authors: Asmita Bhattacharya, Rupkini Sengupta, Sreya Paul [M.Sc. final year, University of Calcutta] * This topic was presented in a Paleontology class lecture, organized in the Department of Geology, University of Calcutta Do you like spiders? What about roaches? Not much? Ok, but there is no reason to hate all arthropods (organism with joint legs; arthros = joint, podos = legs) or get scared when we have our beautiful swimmers of the old Earth. Well, guess the name… yes, I am talking about the ancient ones (i.e., c. 500 million years from today!), Trilobites! Trilobites, a bizarre arthropod of the old Earth (i.e., c. 500 million years from today!), hold the distinction of being one of the first dominant form of complex life in the seas, appearing at a time when the world was just emerging from its "Frozen Planet" state and the seas were ripe for the blossoming of biodiversity. The trilobites earned their place among the arthropods because of its biological beauty and complexity. It's hard exoskeleton (external shells), show a variety of body plans and the external surface shows bizzare sculptures! Trilobites so named not for their distinctive cephalon, thorax and pygidium (head, body, tail), but rather for the three lobes that divide their lateral symmetry. Not to forget the well-developed eyes. In the reign when no Huygen existed, these creatures adjusted the focusing problems even though they had calcitic eyes. Few of the species had eye-shades like the ones we use when distracted by sunlight. Pretty smart!
References
1) AMNH Website on Trilobites. http://www.amnh.org/our-research/paleontology/paleontology-faq/trilobite-website/ 2) Trilobite fact sheet. University of Kentucky. https://www.uky.edu/KGS/fossils/trilob_fact_sheet.pdf 3) Trilobites Facts on BBC. www.bbc.co.uk/nature/life/Trilobite 4) Fortey, R. 2010. Trilobite: Eyewitness to Evolution. Vintage. 5) Raup, D.M. and Stanley, S.M.1978. Principles of Paleontology. Macmillan. |
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