కాంబ్రియన్ నుండి ఒక వింత సాయుధ lobopodian

ప్రారంభ కాంబ్రియన్ సముద్రాలు (542-488 మిలియన్ సంవత్సరాల క్రితం) had a plethora of strange and bizarre creatures almost unimaginable to even the best sci-fi dreamer. Arthropoda పూర్వగాములు బహుశా ఒకటిగా (also Onychophora మరియు Tardigrada), lobopodian పరంపరలో ఒక వింత సమూహం ప్రాతినిధ్యం “కాళ్ళు తో పురుగులు” that once roamed the ancient sea beds. Exactly how close they are to the true arthropods is up for debate (tree below), but this newly discovered genus and species, Diania cactiformis (walking cactus), represents the most well sclerotized and arthropod-like of any known to date.

This whopping two and a half inch monster helps us understand the transition from a soft bodied worm like creature into a hard-shelled arthropod; it also gives a better impression of how diverse these lobopodian appendages may have been. It’s a fascinating question because the advantage of jointed, sclerotized, limbs was one that exploded and diversified amongst the creatures we know today. Exactly how this happened is not any closer to being resolved, but it appears as if the legs of this animal were sclerotized before the body (arthropodization vs. arthrodization). One small fossil discovered and yet another small insight into evolutionary history.

References

Liu, J., Steiner, M., Dunlop, J., Keupp, H., Shu, D., Ou, Q., Han, J., Zhang, Z., & Zhang, X. (2011). An armoured Cambrian lobopodian from China with arthropod-like appendages ప్రకృతి, 470 (7335), 526-530 DOI: 10.1038/nature09704

Further reading: A colleagues blog on the lobopodian in Hungarian.