did-i-mention-the-shirt asked:
After my defeat in beaver butt facts, I've taken some time to think about my demise. I challenge you to more odd animal facts!
Did you know that roughly 100% of animals that give birth are mammals?
Absolutely. For that matter, if you exclude all the insects, fish, reptiles, amphibians and arachnids who give birth to living young and don’t lay eggs, and you don’t count the Platypus or Echidnae (because they do lay eggs) it would be exactly 100%.
Also most sharks and other elasmobranchs (animals with fully cartilaginous skeletons) give birth to live young that grew in eggs inside them, there are exceptions like carpet sharks (they lay eggs on coral or rocks) but that would again lower that percentage to well below 100%. source: am marine biologist and have had to fish those sticky egg purses out of our reef tanks/help catch live newborn spotted eagle rays out of our main tank). I wonder if fish that hold eggs in their mouth where the babies hatch INSIDE the mouth and then are released after a few days also count as live birth… Banggai cardinalfish do this and it’s so cute to see the little heads poking out of dad’s mouth!
Basically, most “facts” we learn in school are in fact… not factual. Or grossly oversimplified. Isn’t that swell?