Fossils of hard mineral parts (like bones and teeth) were formed as follows: o Some animals were quickly buried after their death (by sinking in mud, being buried in a sand storm, etc.). o Over time, more and more sediment covered the remains. o The parts of the animals that didn't rot (usually the harder parts likes bones and teeth) were encased in the sediment. o In the right circumstances (no scavengers, quick burial, not much weathering), parts of the animal turned into fossils over time. o After a long time, the chemicals in the buried animals' bodies underwent a series of changes. As the bone slowly decayed, it was replaced with minerals. o This process results in a heavy, rock-like copy of the original object - a fossil. The fossil has the same shape as the original object, but is more like a rock! At times, it is possible that some of the original bone may remain.

Why are Fossils Rock-Colored? Because they ARE rocks! A fossilized object is just a rocky model of an ancient object. A fossil is composed of different materials than the original object was. During the fossilization process, the original atoms are replaced by new minerals, so a fossil doesn't have the same color as the original object. Fossils come in many colors and are made of many different types of minerals. Also, some fossils of skin (and other soft body parts) have been found. Again, the color of the skin is not retained during the fossilization process, all that remains today is a rocky model of the original.

So how do we know what color dinosaurs were? Or what their eyes looked like? Who decides?

Paleoartists- Those who specialize in extinct animal restoration

Visit paleoartist Tyler Keillor’s website stery.html stery.html

Tiktaalik rosea

The skeleton is then studied to determine as much about the animal as possible. Sometimes, fossilized skin impressions are found with the fossil as well. Paleoartist such as Tyler then get ideas about what the exterior of the animal looked like by looking at the patterns, color, and camouflage of present-day animals. Tyler sculpted this model of what Tiktaalik may have looked like.

Herrerasaurus ischigualastensis was found in Argentina in 1958 by Victorino Herrera, for whom the fossil was named. This skeleton was incomplete, but the discovery of a complete skull in 1988 and additional fragments have provided enough information to make a complete reconstruction.

This reconstruction was created to illustrate a section of a paleoart book, “Life Restorations of Dinosaurs” (2008). Tyler used the well-preserved skull as the starting point. An alert, inquisitive appearance is suggested by the pose, with soft tissues based upon reptilian (reptile) and avian (bird) references, and a coloration scheme inspired by the Komodo dragon.

Article about how Tyler constructs his models: 0magazine%20with%20Tyler.pdf

On left: Fossil specimen of snake in dinosaur egg nest. On right: An illustrated diagram showing where the fossils of the snake and hatchling dinosaur were located at in the nest.

Sketch what your model of this scene would look like. What colors would you use? What position would the snake and baby dinosaur be in? Why?

This hatchling reconstruction is based upon fragmented fossil remains found in a nest of sauropod eggs, associated with the snake Sanajeh. Paleontologist Jeff Wilson used limb bone lengths and egg diameter to determine an estimated size for this dinosaur at hatching. Fossilized embryonic skin from Argentinian sauropods provided reference for the size and shape of scales on the hide

Read an article about the find and related model at:

Paleoartists will at times get ideas for what dinosaurs looked like by studying animal species that survived the great dinosaur extinction, such as alligators and crocodiles: Alligators Crocodiles

It is thought that these animals may have survived the dinosaur extinction because they have the ability to self-heal, live in water, adapt to changes in their environment fairly easily, are cold-blooded, and extremely quick learners. They provide paleoartists with hints about what animals from millions of years ago may have looked like.