Question

What is true of the fossil record of mammalian origins? what is true of the fossil record of mammalian origins? it includes a series that shows the gradual change of scales into fur. it shows that mammals and birds evolved from the same kind of dinosaur. it indicates that mammals and dinosaurs did not overlap in geologic time. it includes transitional forms with progressively specialized teeth?

Answer 1

The fossil record of mammalian origins includes transitional forms like morganucodonts, with features indicating evolution from therapsids. It supports the notion that mammals diversified during the Mesozoic era and that mammals and dinosaurs coexisted. The fossil record shows gradual evolutionary changes, including the specialization of teeth.

Step-by-step explanation:

The fossil record of mammalian origins suggests that mammals evolved from therapsids in the late Triassic period, with the earliest known mammal fossils dating back to the early Jurassic period, around 205 million years ago. One notable transitional form is the morganucodonts, which exhibited transitional features in their jaws, combining reptilian and mammalian characteristics. The fossil record provides evidence for the evolution of differentiated teeth and homeothermy in mammals. Throughout the Mesozoic era, mammals began to diversify, with evidence of small gliding mammals appearing during this time. The fossil record also demonstrates that mammals and dinosaurs overlapped in geologic time, contradicting the statement that they did not.

Detailed records of the fossil record, such as those for horses and whales, show a progression of evolution. The record for horses, for example, includes transition fossils that show intermediate anatomy between earlier and later forms, indicating gradual adaptation to changing environments over millions of years. This narrative is consistent with the patterns observed in the fossil record of mammalian evolution, where transitional forms with progressively specialized teeth are present.

Answer 2

It includes transitional forms with progressively specialized teeth.
The key thing to remember about fossils is: If it's not hard, it's rarely preserved. Now let's look at the options and pick the correct one that matches the known facts.
It includes a series that shows the gradual change of scales into fur.
* This option is rather hard to swallow. There have been a few fossils discovered with soft tissue features, but those fossils are extremely rare. Expecting a record of a gradual change of soft tissues is not likely. So this is a bad choice.
It shows that mammals and birds evolved from the same kind of dinosaur.
* The evidence shows that mammals evolved at the end of the Triassic period from therapsids (about 201 to 250 million years ago). Birds are a relative newcomer with Archaeopteryx being approximately 150 million years ago. So this choice is wrong.
It indicates that mammals and dinosaurs did not overlap in geologic time.
* Nope. Mammals existed throughout the Jurassic period that came after the Triassic period where the first mammals were discovered. So this is a bad choice.
It includes transitional forms with progressively specialized teeth.
* Most definitely. Teeth are nice hard structures that are easily fossilized. And this is the correct choice.