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This is unlikely to ever be definitively known, as the fossil record of early tetrapods is incomplete, and the vast gulf of time that separates us from them (360+ million years) compounds the problem. However, we do have some fossils, and from them it is clear that the earliest tetrapods had more than 5 toes on each foot (they were polydactylous). Acanthostega had 8, Ichthyostega had 7 and Tulerpeton had 6 - there seems to have been a trend of reduction in the number of toes over time in the tetrapod lineage. The early Anthracosaurs seem to have had 5 toes ancestrally, a trait which they might have passed on to their amniote descendants. However, it seems as though even the early tetrapods like Acanthostega were effectively five-toed, as their forward toes were combined into a single flesh-covered digit.
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What does pentadactyl mean?
A limb of an animal with 5 digits (like an arm or a leg)
Do bats have pentadactyl limbs?
Bats do have pentadactyl limbs. Its wing is the forelimb version of the pentadactyl limb. In the bat, the forelimbs have turned into wings for flying by great elongation of four digits, while the hook-like first digit remains free for hanging from trees.
How is homo-logy in the pentadactyl limb evidence for adaptive radiation?
Homology in the pentadactyl limb, where different species share a common limb structure despite having different functions, is evidence for adaptive radiation because it suggests that a common ancestor with this limb structure diversified into various species to adapt to different environments or ecological niches. The conservation of the pentadactyl limb's basic structure implies that these species diverged from a shared ancestor through adaptive changes to exploit different habitats and resources.
What is a pentadactyl appendage?
I will focus on the on the pentadactyl FORELIMB (arm). It is the limb that is common in vertebrates (e.g. humans, birds, dogs, whales, bats ALL HAVE ONE!). It supports the theory of evolution by strengthening the idea of divergent evolution and the idea of a common ancestor by showing that different environmental conditions and different selective pressures can result in vastly different characteristics being selected in common species. Each limb consists of: * humerus - upper arm * radius - forearm * ulna - forearm * carpals - wrist * metacarpals - palm * phalanges - fingers/digits Due to the fact that various organisms have a pentadactyl limb, it is difficult to give a definite answer to what it looks like because it varies from organism to organism. Think of as your own arm as an example of a pentadactyl limb to get a clearer image in your head: * from your shoulder to your elbow is the humerus * from the elbow to the wrist are the ulna and radius * your wrist is the carpal * your palm is the metacarpal * your fingers are the phalanges
Do dogs have pentadactyl?
Yes they do
Do dogs have pentadactyl limbs?
yes they do
Do humans have pentadactyl limbs?
yes
What is the name of the process when a new limb grows on an animal called?
Morphallaxis
When were horses in the us?
Over 55 million years ago horses first evolved. They were only the size of an average dog and they had a pentadactyl limb (finger like structures instead of one hoof as we know today.) This enabled them to walk around as the Earths surface was covered in marshland and they needed the splayed out feet in order to do this, otherwise they would sink and would be unable to run from predators.
How does vestigial structures indicate that present day organisms are different from their ancient ancestors?
The biologist might infer that at one point in history the animal's ancestors had this limb. But as time went by the ancestors used to limb less, therefore, shrinking the limb or completely getting rid of it.
How does an animal reproduce by regeneration?
Some reptiles can regenerate. Lizards have been known to regrow tails, arms, and legs.
What is the root word pentadactyl?
The root word of pterodactyl is tera. This root word means trillion.
