| Speculative biology is simultaneously a science and form of art in which one speculates on the possibilities of life and evolution. What could the world look like if dinosaurs had never gone extinct? What could alien lifeforms look like? What kinds of plants and animals might exist in the far future? These questions and more are tackled by speculative biologists, and the Speculative Evolution welcomes all relevant ideas, inquiries, and world-building projects alike. With a member base comprising users from across the world, our community is the largest and longest-running place of gathering for speculative biologists on the web. While unregistered users are able to browse the forum on a basic level, registering an account provides additional forum access not visible to guests as well as the ability to join in discussions and contribute yourself! Registration is free and instantaneous. Join our community today! |
| Placoderms Take Over; Tetrapod analogue placoderms | |
|---|---|
| Topic Started: Jan 25 2010, 01:38 AM (775 Views) | |
| Toad of Spades | Jan 25 2010, 01:38 AM Post #1 |
![]()
Clorothod
![]() ![]() ![]() ![]() ![]() ![]()
|
So what if toothed gnathostomates went down a path that placoderms did, into decline then extinction, and placoderms took their place as the majority of living vertebrates? Maybe when early tetrapod-like forms appeared, the armor around the head became a sort of thoracic armor to provide support similar to how early land tetrapods had thickened ribs when they were beginning to adapt to land life. Also what if when they eventually became adapted and the armor around the chest became lighter and separates from the head to form something akin to a rib cage. When they evolve into amniote-like forms, they adapt into many lineages like how amniotes lead to many different lineages. Instead of teeth their bony mouth plates adapted to different lifestyles of feeding. Given that tetrapods lead to wildly different descendants like mammals and therapsids, reptiles, dinosaurs and birds, as well as some others, the appearances of tetrapodiform placoderms could very wildly. Imagine a carnivorous 12-foot long quadrepedal creature with hollow, branching feather-like scales, an armored head, an internal vest-like thoracic box, a fully errect dinosaurian/mammalian posture, and a mouth with mutiple sharp pointy front plates, and carnassial-like cheek plates. This is just one extremely tiny example of a tetrapodiform placoderm. Not to mention the whole host of placoderms surviving in the oceans. What are your thoughts on this and what kind of tetrapodiform placoderm or other placoderm creature could you come up with? Edited by Toad of Spades, Jan 25 2010, 02:29 PM.
|
|
Sorry Link, I don't give credit. Come back when you're a little...MMMMMM...Richer. Bread is an animal and humans are %90 aluminum. | |
![]() |
|
| Vultur-10 | Jan 25 2010, 05:44 AM Post #2 |
![]()
|
Very interesting thoughts. Armor as support, interesting. Almost vertebrates with exoskeletons - though they'd have endoskeletons too. |
![]() |
|
| ATEK Azul | Jan 25 2010, 07:54 PM Post #3 |
|
Transhuman
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]()
|
This is very interesting and I would like to contribute, but I don't have any ideas presently to add so I will ponder this and watch the topic for ideas. Hopefully I will be able to add something to here eventually. |
| I am dyslexic, please ignore the typo's! | |
![]() |
|
| Toad of Spades | Jan 25 2010, 09:36 PM Post #4 |
![]()
Clorothod
![]() ![]() ![]() ![]() ![]() ![]()
|
You don't have to post a picture or anything. I just want to know what kind of ideas and descriptions people can come up with. |
|
Sorry Link, I don't give credit. Come back when you're a little...MMMMMM...Richer. Bread is an animal and humans are %90 aluminum. | |
![]() |
|
| Venatosaurus | Jan 25 2010, 10:05 PM Post #5 |
|
HAUS OF SPEC
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]()
|
( This ) is what the world would be like
|
|
| |
![]() |
|
| KayKay | Jan 27 2010, 05:27 AM Post #6 |
|
Adult
![]() ![]() ![]() ![]() ![]() ![]()
|
I remember that! ![]() I don't think they would become tripodal somehow though. I thin they have enough of the fundamental parts to make four limbs. |
![]() |
|
| Vultur-10 | Jan 30 2010, 06:36 PM Post #7 |
![]()
|
It would be interesting to see how land carnivores developed with the weird cutting edges of placoderm 'teeth' or beaks. Hmmm... placo-crocs. Heavily armored semi-aquatic creatures of the alternate Permian, with heads like Dunkleosteus but broader, and powered by huge jaw muscles giving them a bite force like an alligator's or greater. Often large but rarely huge, usually four to ten feet in length depending on age and species, but heavier for that length than modern crocodiles; however they grow throughout life like many fish and reptiles, so exceptional specimens of the largest species can reach fourteen to fifteen feet. They feed on both aquatic and terrestrial animals near the waterside, as crocodiles do today. Placodillos: resembling glyptodonts, armadillos, or ankylosaurs, these heavily armored herbivores use the sharp, bony cutting edges of their beaks to crop tough vegetation. The most common species are as big as a small human or big snapping turtle, somewhere over a hundred pounds, but they range from about housecat-sized to the size of a cow. Again they grow throughout life, so huge long-lived individuals of the bigger species can reach well over a ton, matching the smaller rhinos in bulk. Their guts are large, a giant fermenting vat full of microorganisms allowing them to soften and digest this fibrous plant matter. The placodillos, with these immense guts and heavy armor, are very slow-moving, but they need not flee from predators or chase food. Their main predators are the placo-crocs; though these cannot penetrate the armor of any but the smallest, they can drag the placodillo into the water to drown and begin to decay. The placo-croc sits over the placodile corpse and protects it from scavengers. Once the carcass is soft enough, it can be tugged apart at the joints between armor plates, allowing the placo-croc to feast. This slow method of feeding is suitable for the placo-croc because it has a very low metabolism, like a python, and can live for weeks or longer after devouring a single good-sized placodillo. The placo-crocs also eat slow-moving bottom-feeding placoderm fish, many of which are small enough (and have armor thin enough) that the placo-croc's powerful jaws can actually crush the armor plates. Some large snails are also eaten by the placo-crocs, especially the smaller species. Edited by Vultur-10, Jan 30 2010, 06:38 PM.
|
![]() |
|
| Rick Raptor | Jan 31 2010, 10:37 AM Post #8 |
|
Adolescent
![]() ![]() ![]() ![]() ![]()
|
Wow, those are cool ideas - I especially like the way the placo-crocs kill placodillos. I know crocodiles kill their prey by drowning it, too, but their teeth and powerful jaws already inflict a lot of damage while the heavy-armoured placodillos can only be killed by drowning. |
| [My DeviantArt account] | |
![]() |
|
| Holben | Jan 31 2010, 03:01 PM Post #9 |
![]()
Rumbo a la Victoria
![]()
|
if the croc went and stuck its snout between the plates, it could rip 'em open from the inside. Placoderms wouldn't have modern crocs' jaw-opening problems. |
|
Time flows like a river. Which is to say, downhill. We can tell this because everything is going downhill rapidly. It would seem prudent to be somewhere else when we reach the sea. "It is the old wound my king. It has never healed." | |
![]() |
|
| Vultur-10 | Jan 31 2010, 11:05 PM Post #10 |
![]()
|
I think the plates are closer together than that. They're supposed to have Dunkleosteus-looking beaks, they wouldn't be great for prying things apart; I think the sharp tip would slip out from between the plates. |
![]() |
|
| 1 user reading this topic (1 Guest and 0 Anonymous) | |
| « Previous Topic · Alternative Evolution · Next Topic » |











7:19 PM Jul 10