One of these things is not like the other…
First row: Walrus (Odobenus rosmarus) skeleton
Second row: Hooded seal (Cystopkora cristata) skeleton
Third row: Dugong (Dugong dugon) skeleton, Brazilian sea lion (Otaria flavescens) skeleton.*Skulls depicted are of species in the same genus as the skeleton.
Sirenia (manatees, dugongs, and sea cows) and Pinnipedia (the seals, walruses, and sea lions) are often seen as very similar, but they came from very different lineages.
While both came from land mammals (just like all sea mammals), the pinnipeds evolved from a bear-like ancestor, who returned to the sea around 28 MYA. They’re Caniformidae, or dog-like Carnivora.The sirens evolved from the same ancestor as the hyraxes and elephants, and returned to the sea around 50 MYA. They’re only distantly related to Cetaceans and Pinnipeds.
Vergleicheende Osteologie. Edward D’alton, 1821.
(via biomedicalephemera)
- radicalbison reblogged this from biomedicalephemera
- toni106 liked this
- loveliliannah liked this
- im-huge-and-stupid liked this
- autistic-zombie liked this
- asami1028 liked this
- earthwax liked this
- seadragonsoda liked this
- pissfizz liked this
- minecrafttortie liked this
- love-rosh liked this
- jedi-giraffe liked this
- robinzanders reblogged this from biomedicalephemera
- merry-melody liked this
- the-modern-maenad liked this
- colourful-artist-love liked this
- domoniki-11-11 liked this
- derangedbutterfly reblogged this from biomedicalephemera
- leeuwenhoeka reblogged this from curse-of-the-pharaohs
- endquire reblogged this from curse-of-the-pharaohs
- endquire liked this
- curse-of-the-pharaohs reblogged this from biomedicalephemera
- clnyphotostream liked this
- coonazz74 liked this
- dragonjules22 liked this
- btdmbt liked this
- sugarcucumber liked this
- dcdreamer23 liked this
- floral-oboe liked this
- carrot-gallery liked this
- in-a-trans-like-state liked this
- femme-vampire liked this
- theweddingofthefoxes reblogged this from cyrsed
- prismaticjelly liked this
- ahni-animalia reblogged this from biomedicalephemera
- hatsuneme liked this
- cyrsed reblogged this from biomedicalephemera
- pantamallion reblogged this from biomedicalephemera
- lostinthemeshes liked this
- honey-b-b reblogged this from honey-b-b
- biomedicalephemera posted this
- Show more notes