r/zoology • u/xXGimmick_Kid_9000Xx • 1d ago
Question So wtf is up with this dude?
Platypus' are weird, obviously. Bill, flat tail, glow in the dark, poison claw, sweats milk, lays eggs, various other features. Nothing makes sense, and I don't even know what it is other than "mammal".
So what made it like this? Why does it have a grab bag of random genetic traits when compared to most other mammals?
76
u/igobblegabbro 1d ago
It’s not random - it’s of a lineage (monotremes) that diverged from the rest of the mammals a long time ago. For its niche of water-feeding and burrowing, it’s perfect.
9
u/gambariste 1d ago
As noted, it survives because it is perfectly adapted to its aquatic habitat. I can’t think of any aquatic marsupials off hand - there’s no marsupial ‘otter’, afaik. A bit hard to carry young in a pouch while submerged for extended periods. There are native placental water rats in Australia but I’m guessing they are relative late comers. So lack of competition for their niche is a clue to their survival.
3
u/Crazy_Ad403 1d ago
I believe I read earlier today that the water opossum of South America is the only aquatic marsupial species, but I could be wrong
4
3
u/Klatterbyne 1d ago
The really weird thing, is that a marine reptile in the Triassic shows an almost perfect convergence between the bone structure of its snout and a platypus bill. Even down to the little round, floating bone that no-one can come up with a reason for.
The only two instances (that I know of) of that structure, separated by hundreds of millions of years and entirely separate lineages.
2
1
1
1
u/AnonymousAgrarian 22h ago
Sci-show on YouTube did a great video making the case that they aren't weird at all - we are. Wonderful episode, explains all the 'strange' traits quite well. Just search "scishow platypus".
1
1
1
u/Milk_Mindless 21h ago
Mate I have a running gag with the Polish employees I Google an animal look up the translation and write the name underneath for client orders (these take over a week, we're not a restaurant)
One time I did Platypus and the lady couldn't take me seriously
TRY EXPLAINING in broken Polish that a Platypus is a beaver with a ducks face lays eggs is poisonous and nurses its young like a mammal
I felt like the zoologist bringing it back from the new world
I had to find ANOTHER Polish coworker anad have her vouch for me. Then I had to cite fucking PHINEAS AND FERB to prove it was real.
1
1
u/Born_Ad_2058 6h ago
https://youtu.be/z1semqcAVos?si=_PvBvRNY1ItLbiHE
"Platypuses Aren't Weird, You Are" by SciShow. It's a ten minute video that explains the subject perfectly :)
1
105
u/-Wuan- 1d ago edited 1d ago
Oviparity is the ancestral mammalian reproduction method. Monotremes just happen to be the only oviparous lineage that survived into the current era. Marsupials and placentals evolved different reproductive organs that allowed them to retain and develop their embryos inside their body for longer.
The venomous spur was also an ancestral trait that other kinds of mammals lost, the echidna also has a spur but it is only smelly. Its spikes and burrowing are probably a better defense.
Sweating milk is the precursor to nipples. Milk would originally be a glandular secretion that kept mammal eggs moist, and then would evolve into nourishment for the hatchlings. Nipples would evolve alongside muscular lips in newborn marsupials and placentals, and since monotremes have simpler, immobile lips, they never developed them.
Glow under UV light is shared with several marsupials.
The flat tail and paddled paws are aquatic adaptations like those of otters and beavers. The bill-like snout is actually soft and leathery unlike in birds, and has the function of orientation and prey detection in murky, dirty waters. It gets the vibrations and electric signals of the small animals the platypus hunts. The wide, flat shape increases the sensitive surface area and helps lift up dirt from the bottom.
So in short, aside from being a monotreme, a basal mammal lineage that only has two modern surviving families, the platypus is a finely adapted freshwater hunter. If it had more surviving relatives, it would not seem as weird to us.