Your favourite "living fossils"?

[Thunderbird]

Hoatzin: Guyana's Prehistoric Throwback
The Hoatzin is a strange primitive bird. The Hoatzin's plump body and reddish-brown feathers may not appear antediluvian, but the bird's blood-red eyes set in patches of bright blue skin and unruly crest of long feathers are throwbacks to another time. Hoatzins are also born with two prehistoric claws protruding from their wings, a characteristic that lead many to believe that it's a direct link to the Archaeopteryx, the first known bird. Hoatzins are found along rivers and creeks in the Upper Demerara River-Berbice area in Guyana, and are easily seen because they often live in large groups and rarely stray far from their principal locals, probably due to the fact that they're poor fliers. Indeed, Guyana's national bird is such a bizarre species that it was put in its own order, the Opisthocomidae.

[Moontanman]

The entire domain of Archaea microbes.

[Thunderbird]

Originally Posted by Moontanman

Any one who has been flogged by a rooster should be able to see the relationship quite well, the little bastards would be dangerous if they had teeth

Thats kinda how I realized they were indeed dinosarus.
One day I was moving chickens from one pen to another for my father inlaw. I picked a chicken up and just looked at it. I said to my father inlaw that I had just realized that I was holding a dinosaur. He gave me a Look and said
" Its a chicken". like I was being an idiot.

[freeztar]

Equisetophyta

[questor]

COCKROACHES! Cockroaches
Copyright 1998 by Edward Willett
Steven Spielberg missed a bet with his movie, Jurassic Park. He focused on the age of dinosaurs. If he really wanted to freak people out, he'd focus on a much earlier era, the Carboniferous Period: a.k.a. "The Age of Cockroaches."

Yes, cockroaches, those scuttling, light-fearing pests we've all encountered at one time or another, were once the predominant insect on the planet, and if their place in the evolutionary hierarchy has slipped a little, it shouldn't be taken as evidence that they are lacking in survival traits: they've hardly changed in the 320 million years since they first appeared on the planet. That's a pretty good indication that their design continues to be effective.

If they are that old, why aren't they walking upright with large cranial capacity? Did evolution pass them by?

[Moontanman]

Originally Posted by questor

COCKROACHES! Cockroaches
Copyright 1998 by Edward Willett
Steven Spielberg missed a bet with his movie, Jurassic Park. He focused on the age of dinosaurs. If he really wanted to freak people out, he'd focus on a much earlier era, the Carboniferous Period: a.k.a. "The Age of Cockroaches."

Yes, cockroaches, those scuttling, light-fearing pests we've all encountered at one time or another, were once the predominant insect on the planet, and if their place in the evolutionary hierarchy has slipped a little, it shouldn't be taken as evidence that they are lacking in survival traits: they've hardly changed in the 320 million years since they first appeared on the planet. That's a pretty good indication that their design continues to be effective.

If they are that old, why aren't they walking upright with large cranial capacity? Did evolution pass them by?

During that period they also had spiders the size of dogs and centipedes 10 feet long. Evolution has no goals only survival of the fittest. Roaches are not the only arthropods that have survived relatively unchanged since then.
Dragonflies
spiders
silverfish
millipedes
centipedes
scorpions
isopods
The list is quite long

[Eclogite]

We should be careful not to presume superficial phenotypic similarities are tantamount to genotypic near identity.

[Thunderbird]

Originally Posted by Eclogite

We should be careful not to presume superficial phenotypic similarities are tantamount to genotypic near identity.

Such as the Hoatzin, bird at the top of the page?

[Mercedes Benzene]

My favorite is the Horseshoe Crab. Not only are they wicked cool-looking, but they've been really helpful in biomedical research! As a kid, I used to go to see them at the beach. Thousands would swarm the beaches, and I'd help flip them right-side-up when they got stuck on their backs. Good times.
Horseshoe crab - Wikipedia, the free encyclopedia

[mynah]

Originally Posted by Thunderbird

Thats kinda how I realized they were indeed dinosarus.
One day I was moving chickens from one pen to another for my father inlaw. I picked a chicken up and just looked at it. I said to my father inlaw that I had just realized that I was holding a dinosaur. He gave me a Look and said
" Its a chicken". like I was being an idiot.

Hen's (or rooster's) teeth are not as far-fetched as one might think.

Mutant chicken grows alligator teeth

Elsewhere, they have also been compared to dinosaur teeth. Apparently the genes for teeth are still intact, but something went missing upstream some 70 to 80 million years ago. As interesting to me would be why regaining teeth should be associated with severe defects leading to death in late embryonic development.

Speaking of animals with bills, let's not forget the monotremes, living remnants of a time when mammals still lay eggs and had milk, but no nipples.