If no Dinosaur fossils can be found above the KT boundary, how can we know birds evolved from them?

Answer 1

The first known feathered dinosaurs from the fossil record are the Maniraptorans, 190 million years ago. From the process of feather evolution known from molecular genetics, we know that feathers first evolved as a means of thermoregulation (keeping warm). The aerodynamic property of feathers did not come into play until much later. The Maniraptorans left many descendants including the Velociraptors and the Tyrannosaurids. Another one of their descendants evolved into a group known as the Enantiornithians (125-165 million years ago). These were half bird/half dino animals that typically had feathers and wings, but their head, teeth, claws, tail and feet were dino-like. Archaeopteryx was one species of Enantiornithian. One descendant of the Enantiornithians gave rise to the Ornithurians (90-135 million years ago) also known as proto-birds. Ornithurians were fairly bird like, but still had reptilian teeth. One descendant of Ornithurian gave rise to Neornithes about 120 million years ago. Neornithes evolved to become all modern birds.

Several species of Neorinthes survived the K/T mass extinction event (65 million years ago). All dinosaurs became extinct. Birds are the only surviving, direct descendant of the dinosaurs.

Answer 2

First, we can never "know" what happened 60 to 40 million years ago, we can only make an educated guess. And what science has done is systemetized how we make those educated guesses. We may not be right, but at least the same criteria is being applied to each guess and there are either ones that are better supported or ones who are not supported at all.

The answer to your question is Cladistics. Cladistics is the hierarchical classification of species based on evolutionary ancestry. These classifications are built from species characteristics. Some of those characteristics were mentioned by others, such as feathers, or the development of the hyoid bone (also called the wish bone). Along with what we know about biology, cladistics can tell us which animals are more likely related than others. For instance, birds and mammals cannot be very related because the development of hair and feathers must be mutually exclusive. Although we do not find evidence of dinosaurs beyond 60mya, there is evidence of other dinosaur like animals that share many common characteristics of birds. These dinosaur like animals are a "missing link" of sorts.

I think you are getting caught up in the term dinosaur. Yes, it's a very specific term, but it doesn't mean there aren't any dinosaur like fossils found at an earlier date.

By the way, Bird did not evolve from Dinosaurs, they mearly shared a more recent common ancestor than something like mammals and birds.

Answer 3

tiger b gave a very good answer above, but unfortunately is wrong when she says that birds and dinosaurs simply shared a common ancestor.

It's clear from modern cladistics that birds are actually directly descended from dinosaurs - or rather, from a particular group of dinosaurs, the theropods (which include Tyrannosaurus).

From Wikipedia: "Among the features linking theropods to birds are the three-toed foot, a furcula (wishbone), air-filled bones and (in some cases) feathers and brooding of the eggs."

So from a cladistic point of view you could say that birds *are* dinosaurs (just as humans are apes), and so it's not true that no dinosaur fossils can be found above the K-T boundary - because we find bird fossils after that date.

Answer 4

Birds evolved in the Jurassic, many millions of years before the KT boundary.

Answer 5

I'm not a geologist or a paleontologist, BUT I think it is a fair assumption that birds evolved from reptiles. The question is did they evolve from the dinosaur type of reptile.

The skeletal similarities would suggest so. I think it is simplistic to think the jump from dinosaur to bird was a quick one, even if some dinosaurs were found to have feather-like scale modifications. There could have been many intermediate stages and these intermediate stages could have existed in small localised areas where these adaptations were advantageous, hence the lack of abundant fossils.

So dinosaurs as we know them could have gone extinct after the intermediate reptile/bird forms had already evolved, but birds proper had not.

Answer 6

as a responce to the last answer...

do be aware that there are MANY websites out there with missleading so called "scientific" information...
they are writen ONLY for the perpose of confusion.

they often are writen with hidden agendas. by people who see science as the cause of all imoral parts of modern life.

evolution... is as close to scientific "fact" as you can get
because: it can be tested.

the creationist argument canot be tested; it is literaly a matter of "faith"

matters of "faith" should not be discussed in the subject of science

...
to answer your question

birds evolved from dinosaurs, before the KT boundry
(many fossil birds have been found before the KT boundry i.e. new stuff from china)

birds contiuned, dinosaurs did not

Answer 7

Dinosaurs did not evolve from birds or reptiles. They were created as dinosaurs.
There are two camps of evolutionists - each camp can demonstrate that dinos did not evolve from the other, as it were.
Archaeopteryx is not a missing link - it is a bird, plain and simple.

Those that think the dinosaurs died out millions of years ago are perhaps unaware of the large amount of evidence indicating that they lived recently alongside man.

There are many written accounts and depictions of dinosaurs.
http://www.genesispark.org/genpark/ancient/ancient.htm
Remember that the word dinosaur was invented in 1841. Before that people used names like dragon.
People from all over the world have accounts of dinosaurs: the Chinese who have incorporated it into their lunar calendar, The Welsh who have the dragon in their flag; The account of the Saxon Beowolf; The native american thunderbird; and other stories from many other nations. The Romans even made mosaics of them.

Furthermore, dinosaur fossils have even been found containing blood cells - hardly 65 million years old.
http://www.googlesyndicatedsearch.com/u/creationontheweb?q=dino+blood&hl=en&lr=

But check the evidence for yourself - don't by brainwashed by dogmatic evolutionists who don't want us to think for ourselves :)
http://www.creationontheweb.com/content/view/3061

Answer 8

New discoveries have shown that many dinos were covered in down (feathers) like the T-rex. Both birds and reptiles have scales, lay eggs, have nucleated red blood cells, and have skeletal similarities. Archaeopteryx was a bird in the Jurassic but was so reptilian looking that scientists identified it as a dino at first. There are many similiarities that make it seem like they are cousins. This is why theories are fun - the discussion!

Answer 9

i never knew about the KT boundary....but, there's a fossil bird ARCHEOPTERYX that reveals the relation between reptiles and birds...it has scales in it's body like a mammal, but has wings to fly!!!!

refer this site
http://66.218.69.11/search/cache?ei=UTF-8&p=archaeoptryex+fossils&y=Search&rd=r1&meta=vc%3Din&fr=yfp-t-501-s&fp_ip=IN&sado=1&u=en.wikipedia.org/wiki/Archaeopteryx&w=archaeoptryex+archaeopteryx+fossils&d=bmKJrPL9Pylq&icp=1&.intl=us