#finally.... asks....

if you hugged a tiktaalik would you hug it like this:

or this:

killed too many legends

IN MEMORIAM:

blastoids

eurypterids

trilobites

the verdict is:

youre shitting me theres no way this thing was real

what the fuck

i dont know what the biggest source of discourse in paleontology as a whole is, but one that i see come up a lot is the nanotyrranus debate.

basically, theres a controversy over whether nanotyrranus warrants its own taxonomic classification or if its just a juvenile tyrannosaurus rex. im on team juvenile t-rex.

this is opabinia. the absolute magnum opus of evolution. when the body plan was revealed at a presentation, the entire audience laughed. and for a while, nobody knew what ecological niche it could possibly have filled. however, the finding and analysis of opabinia revealed a wealth of information about the diversity of early life on earth.

opabinia has an extremely unique body form, with a hollow proboscis, 15 body segments, and five eyes. “how the hell did this happen?” you may ask. the same question was asked by paleontologists studying the cambrian explosion. and the answer was very important to our understanding of the first major diversification of animals.

the researcher whittington, who introduced the modern design of opabinia, stated that it, along with other cambrian creatures, didnt “fit” into any modern taxonomic groups. this hinted at something important; early life was unusually experimental, which meant that it was possible that unusual evolutionary mechanisms were at play at the time.

stephen jay gould (one of the most important paleontologists of all time) wrote that

I believe that Whittington’s reconstruction of Opabinia in 1975 will stand as one of the great documents in the history of human knowledge. How many other empirical studies have led directly on to a fundamentally revised view about the history of life?

We are awestruck by Tyrannosaurus; we marvel at the feathers of Archaeopteryx; we revel in every scrap of fossil human bone from Africa. But none of these has taught us anywhere near so much about the nature of evolution as a little two-inch Cambrian oddball invertebrate named Opabinia.

(from a wonderful life, which he wanted to call homage to opabinia)

the long and short of it is:

there is no hard fast line where one taxon stops and another begins; rather, there are evolutionary transitions. what that means is that the change from fish to tetrapods (the group containing reptiles; reptiles didnt evolve directly from fish themselves) happened very gradually to an extent that there is no species that can be hailed directly as the first tetrapod, which is why when youre reading about evolutionary transitions, they always say one of the first.

its like this gradient:

where does the blue stop? where does the purple start? the answer is that there isnt a clear line that has blue and blue only to its left and purple and purple only to its right.

its similar when talking about the fish to tetrapod transition. theres a reason organisms like tiktaalik and archaeopteryx are called transitionary organisms; they have x and y traits of one group and b and c traits of another.

look; the creature at the bottom is 100% fish and the creature at the top is 100% tetrapod, but in between? theres no immediate shift from fish to tetrapod, and the same goes for the vast majority of transitions.

@xwiing

these are bones, and they’re considered to be subfossils.

that means that they havent been fossilized through fossilization methods like permineralization, casting. etc., but they are still remains of a once-living organism– the definition of a fossil.