Ancestor of all animals identified in Australian fossils

March 24, 2020 7:39 AM

A team led by UC Riverside geologists has discovered the first ancestor on the family tree that contains most familiar animals today, including humans. The tiny, wormlike creature, named Ikaria wariootia, is the earliest bilaterian, or organism with a front and back, two symmetrical sides, and openings at either end connected by a gut.
posted by Etrigan (21 comments total)

You know, we may have our differences, but let's not forget that when it comes down to it, you and I are both organisms with a front and back, two symmetrical sides, and openings at either end connected by a gut.
posted by LobsterMitten at 7:43 AM on March 24, 2020 [55 favorites]

Fascinating. In other unexpected news, an animal without mitochondria has been discovered.
posted by bouvin at 7:55 AM on March 24, 2020 [3 favorites]

We are now at the point where copies of Stephen J. Gould's Wonderful Life should carry a warning sticker.
posted by thatwhichfalls at 8:11 AM on March 24, 2020 [2 favorites]

I have never had such a strong desire to change my username before.
posted by bleep at 8:45 AM on March 24, 2020

We are now at the point where copies of Stephen J. Gould's Wonderful Life should carry a warning sticker.

We've come a long way from "Oh f__k, another phylum" to "Ok, relatives of onycophora and arthropoda"
posted by kurumi at 8:50 AM on March 24, 2020 [1 favorite]

So we are all ultimately Australians?

Crikey.
posted by ricochet biscuit at 8:52 AM on March 24, 2020 [4 favorites]

LobsterMitten: "[...] but let's not forget that when it comes down to it, you and I are both organisms with a front and back, two symmetrical sides, and openings at either end connected by a gut."

Not so fast!
posted by Hairy Lobster at 9:08 AM on March 24, 2020 [3 favorites]

let's not forget that when it comes down to it, you and I are both organisms with a front and back, two symmetrical sides, and openings at either end connected by a gut.

Some days, that is the limit of my aspirations.
posted by GenjiandProust at 9:10 AM on March 24, 2020 [12 favorites]

Nice going, Ikaria wariootia.
posted by praemunire at 9:30 AM on March 24, 2020 [1 favorite]

Some days, that is the limit of my aspirations.

Don't feel bad about that. It took a long time to get there and it's proved pretty successful.
Be proud you have the good taste to be bilaterally symmetrical!
posted by thatwhichfalls at 9:32 AM on March 24, 2020 [3 favorites]

It's a wonderful discovery. I have an amateur fascination with the urbilaterian, particularly what its nervous system would have been like. This fossil fits neatly with some hypotheses, and its differentiated anterior-posterior axis is particularly exciting.

I know they named it after local geographical features, but with my minimal Latin I can't help reading wariootia as "Wario-ear".
posted by biogeo at 9:39 AM on March 24, 2020 [1 favorite]

kurumi: We've come a long way from "Oh f__k, another phylum"

Link is broken?
posted by clawsoon at 9:49 AM on March 24, 2020

openings at either end connected by a gut

It would be difficult to find a less romantic description of us.
posted by gwint at 10:11 AM on March 24, 2020 [1 favorite]

You know, we may have our differences, but let's not forget that when it comes down to it, you and I are both organisms with a front and back, two symmetrical sides, and openings at either end connected by a gut.

I'm playing D&D tonight, and shame on me if I don't find an opportunity to work this line in somewhere.
posted by Gelatin at 10:43 AM on March 24, 2020 [5 favorites]

If as the article says I. warioota was more complex than its contemporaries, wouldn't there have been a bilateral organism predating it that hasn't been observed yet? Or maybe it had other bilateral cousins. Or even maybe it could've been a failed lineage and something else was the real earliest ancestor.
posted by polymodus at 11:54 AM on March 24, 2020

Finally we have someone to blame
posted by The otter lady at 12:13 PM on March 24, 2020 [4 favorites]

You know, we may have our differences, but let's not forget that when it comes down to it, you and I are both organisms with a front and back, two symmetrical sides, and openings at either end connected by a gut.

I embrace the kinship of all bilaterans, with our highly conserved HOX genes and our common ancestor. Even the starfish and octopodes who have gone their own way. In our diversity lies our beauty! We're all siblings, under the development signalling pathways.

Not the cnidarians though. They aren't part of our club, the smug foreign bastards.
posted by mark k at 2:28 PM on March 24, 2020 [7 favorites]

Ikaria Wariootia was one my favorite arcade games when I was a kid.
posted by etc. at 7:46 PM on March 24, 2020 [3 favorites]

Yeah, the cnidarians and the ctenophores both, with their arrogant silent C's and their pompous gelatinous body plans.
posted by biogeo at 11:47 PM on March 24, 2020 [3 favorites]

So we are all ultimately Australians?
Some people think so.
posted by Thella at 12:22 AM on March 25, 2020

It would be difficult to find a less romantic description of us.

Try this.
posted by Johnny Wallflower at 7:45 AM on March 25, 2020