Mailing List Archive Mailing List Archive
From: scuba <scuba@uc*.be*.ed*> wrote on Thu 7 Jul 1994 03:31:04 -0700 (Subject: Old News On Ecology & Nature):- > I post collections of news stories that I think may interest divers ... > Second..ANCIENT WALKING WHALES... Paleontologists in Pakistan have unearthed what appears to be the missing link between the walking ancestors of the current whale evolutionary line. The 50 million year old sea lion sized fossil is the first whale type found with functional hind limbs and feet, and has been named Ambulocetus natans - early walking cetacean. Other later whales may have come on land. The odd sea-serpent-like shape of the well-known large archaeocete whale Zeuglodon alias Basilosaurus, and its recently discovered diminutive but complete hindlegs, lead me to think that despite its size it could haul out and may have given birth on land like seals. If it lived always in the water, likely it would have evolved to a fully whale shape sooner. A popular description that I was aside that it had "[fore] flippers like a seal's", i.e. able to prop its chest off the ground to allow movement and breathing ashore. (Would a palaeo-anatomist please confirm or deny?) Perhaps the young had hind legs big enough to make them more agile on land to keep up with their mothers and to keep away from being run over. But later the back legs spoilt the streamlining, so they stayed at baby size as the animal grew to adulthood. It may have taken whales a long time to evolve their peculiar brain neuroanatomy and function that lets them live without needing REM sleep (= dreaming, which can't happen safely in water). Before that, they had to haul out sometimes to catch up with their need for REM sleep, and the long thin shape was to let them move about ashore easier. A fully grown Basilosaurus hauling out must have been quite a sight! Addendum: Could coral reef death sometimes be partly due to removal of sharks letting coral-eating fish get too many and eating the coral out?, like the deer in Yellowstone Park getting too many and eating the grazing out after Man wiped out the wolves there.
Navigate by Author:
[Previous]
[Next]
[Author Search Index]
Navigate by Subject:
[Previous]
[Next]
[Subject Search Index]
[Send Reply] [Send Message with New Topic]
[Search Selection] [Mailing List Home] [Home]