Some good questions from Samuel

We recieved a very nice email from Samuel Roy. In it he asked some good questions about dinosaurs:

Do you know where they came from? Can you tell me why we can't see them anymore? I think it would be cool to see a dinosaur, don't you? How old is the oldest dinosaur by the way?

We aren't experts, but this is what we think so far. Dinosaurs evolved from early lizards (reptiles) like Ichthyostega. (The picture is from Early Tetrapod Research at Cambridge University, UK.)


The oldest dinosaur we know of is Herrerasaurus (235 million years) followed closely by Eoraptor (228 million years).

We can't see dinosaurs today because they went extinct at the end of the Cretaceous period, 65 million years ago. No one really knows what caused the extinction of the dinosaurs. A lot of scientists think that a huge comet hit the earth and caused it. But our mom read an article the other day by a scientist who studies ancient pollen and he said that there seemed to be some really bad things happening even before the comet. There was a lot less pollen around for quite a while before the comet. And she explained to us that it probably means the plants that the dinosaurs ate were having a hard time growing. (Sorry, mom forgot to furl the article. If anyone knows the link, i'd love to include it.)

There are some animals that were around with the dinosaurs that we can still see today--the Tuatara of New Zealand is one. It has been around pretty much unchanged for 225 million years.



Others are crocodiles, sea turtles and sharks.

And, yes, we think it would be really cool to see a dinosaur.

A new blog to add to our roll!

Fellow dino fan afarensis just pointed us to a great blog about fossils of all sorts called Transitions: The Evolution of Life. You've got to check it out!

And the life-size model of T-Rex at the Boston Museum of Science looks really awesome. We hope we get to visit it someday, too! Thanks Phobos for telling us about it!

Alligator or Crocodile

We have been having lots of fun learning about Alligators and Crocodiles and we wanted to share the answer to the question we hear most adults asking. How can you tell the difference between an alligator and a crocodile?

In a crocodile the fourth tooth on the lower jaw is visible. But the full answer in colour with lots pictures is here at Alligators vs. Crocodiles. There is a fantastic guide available from Environment Canada here. It is prepared for customs officers who have to help protect all of the endangered species of crocodilians. It shows how to identify all the different species of alligators, crocodiles, caimans, and gharials. We didn't know there were so many.

And we really like this site, Crocodilians: Natural History. It has all sorts of great facts, pictures, and even movies of crocodiles. Their links page is a great resource for learning anything you might want to know about crocs.

Crocodiles are living dinosaurs. They have been around since the Late Triassic (about 225 million years ago). There is a neat site called The Archosauria that has info about the ancient crocodile ancestors.

We got interested in crocodilians again because we got to pet one at a show recently put on by Safari Jeff and Safari Shannon from Great Green Adventures. One of our other favourite Crocodilian shows is with Chris and Martin Kratt and Zoboomafoo.

A Russian Dinosaur discovered!

a dino in Moscow, originally uploaded by raffi_1970.

This is our friend Raffi's T-Rex. Rrrroooaaarrr! We love it!

The amazing fossils of Messel

We went to a talk by paleontonlogist Graham Beard last weekend. He talked and showed us lots of slides about the fossils people are digging up at a place called Messel, in Germany. It is a World Heritage site. We were really interested in the bugs, opposums, bats, turtles, crocodilians, and cute little mammals that they are finding. We also liked being able to touch the fossils and animal skeletons that he brought.

The book about Messel is called, Messel: The Pompeii of Paleontology. (We think, we will correct this if we are wrong.) You might be able to find it at your local library.

Here are some sites where you can learn more about these amazing fossils. Some of them are in German, but the pictures are great.

A site that tells you a bit about the fossils and the site. (Some of the links on this page don't work.)

The Fossil Museum site is really neat and has a page on Messel.

Site of the Messel research team.

An article from Science Daily about the possible causes of the mass deaths at Messel.