21Sep 2022 by Nigel Fleming No Comments
linkedin post 2020-09-12 03:47:01

linkedin post 2020-09-12 03:47:01

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TRANSITIONAL WHALES. "Protocetidae are middle Eocene (49–37 Ma) archaeocete predators ancestral to later whales. They are found in marine sedimentary rocks, but retain four legs and were not yet fully aquatic. Protocetids have been interpreted as amphibious, feeding in the sea but returning to land to rest." http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0004366 View in LinkedIn
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21Sep 2022 by Nigel Fleming No Comments

linkedin post 2020-09-12 03:43:34

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TRANSITIONAL FOSSILS. “Discovery of a near-term fetus positioned for head-first delivery provides important evidence that early protocetid whales gave birth on land. This is consistent with skeletal morphology enabling Maiacetus to support its weight on land and corroborates previous ideas that protocetids were amphibious. Specimens this complete are virtual ‘Rosetta stones’ providing insight into functional capabilities and life history of extinct animals that cannot be gained any other way.” https://lnkd.in/dKz_vTv View in LinkedIn
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21Sep 2022 by Nigel Fleming No Comments

linkedin post 2020-09-12 03:42:51

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TRANSITIONAL FOSSILS. “Discovery of a near-term fetus positioned for head-first delivery provides important evidence that early protocetid whales gave birth on land. This is consistent with skeletal morphology enabling Maiacetus to support its weight on land and corroborates previous ideas that protocetids were amphibious. Specimens this complete are virtual ‘Rosetta stones’ providing insight into functional capabilities and life history of extinct animals that cannot be gained any other way.” https://lnkd.in/dKz_vTv View in LinkedIn
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21Sep 2022 by Nigel Fleming No Comments
linkedin post 2020-09-12 03:39:51

linkedin post 2020-09-12 03:39:51

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EARLY CETACEANS. "Their features became adapted for living in the marine environment. Major anatomical changes include streamlining of the body, the migration of the nasal openings towards the top of the cranium, the shrinking and eventual disappearance of the hind limbs, the modification of the forelimbs into flippers, and the growth of flukes on the tail." http://www.crystalinks.com/fossilwhales.html View in LinkedIn
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21Sep 2022 by Nigel Fleming No Comments

linkedin post 2020-09-12 03:35:59

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WHALE ANCESTORS. "All cetaceans, including whales, dolphins and porpoises, are descendants of land-dwelling mammals of the Artiodactyl order (even-toed ungulates). Both are related to the Indohyus, an extinct semi-aquatic deer-like ungulate, from which they split around 54 million years ago. These primitive cetaceans first took to the sea about 50 million years ago and became fully aquatic about 5-10 million years later." https://lnkd.in/d3tQ2S7 View in LinkedIn
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21Sep 2022 by Nigel Fleming No Comments
linkedin post 2020-09-12 03:33:56

linkedin post 2020-09-12 03:33:56

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LAND ANCESTORS OF WHALES. "Although early whale fossils had been known at least as early as the 1830s, they were often mistaken for giant marine reptiles, as evidenced by the genus name Basilosaurus (Greek for ‘king lizard’), a long, snake-like whale from the Late Eocene [38–34 million years ago (Mya)]." https://www.researchgate.net/profile/Michael_Mcgowen/publication/275671338_A_Whale_of_a_Tale/links/558bce1608ae681f47160178.pdf View in LinkedIn
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21Sep 2022 by Nigel Fleming No Comments

linkedin post 2020-09-12 03:32:02

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AMPLE FOSSIL EVIDENCE. "A number of important fossil finds in the 1980s to 2000s revealed several forms that displayed an elegant sequence of incremental adaptations to life beneath the waves. Since then, the evolution of cetaceans has emerged as an example of one of the most well-documented phenotypic transitions in the vertebrate fossil record." https://lnkd.in/d-3T5AM View in LinkedIn
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21Sep 2022 by Nigel Fleming No Comments
linkedin post 2020-09-12 03:30:32

linkedin post 2020-09-12 03:30:32

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TRANSITION TO LAND. "Many amniote groups (e.g. sauropterygians, squamates, cetaceans, sirenians, pinnipeds) made the evolutionary transition from a fully terrestrial to a semi- or fully aquatic life. This required major morphological and physiological changes that are best developed in the most specialized aquatic forms, like extant cetaceans and sirenians, which now live totally independent of the terrestrial environment." http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0118409 View in LinkedIn
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21Sep 2022 by Nigel Fleming No Comments
linkedin post 2020-09-13 03:22:40

linkedin post 2020-09-13 03:22:40

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FAST MATURITY. "The presence of partially mineralized permanent first molars in the fetal skull indicates precocial development, which may have been a key life history trait in early whales facilitating the transition from land to sea." (Precocial species have relatively mobile babies). http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0004366 View in LinkedIn
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