Ask the Experts: Where are the dinosaurs?

This is one of our most popular questions!

The main reason we do not have any dinosaur fossils at the Western Center is because there were none found in this area. The Western Center focuses on the paleontology of the surrounding Riverside County region, which has had very little in the way of dinosaur finds.

The landscape during the time of the dinosaurs was much different than it is today. The area that is now Riverside County was completely underwater during the time of the dinosaurs, which paleontologists call the Mesozoic Era (made up of the Triassic, Jurassic and Cretaceous Periods). This alone makes dinosaur fossils a very rare occurrence in Southern California. It wasn’t until much later, during the Ice Age, that our region was above the water and able to be inhabited by many of the animals we see in the museum today.

(Image: California during the Jurassic Period. Aerial image courtesy of Department of Geology, Arizona State University)

DA

Ask the Experts: Why are some animals extinct and others arent?

While it may not seem like it on the scale of a human lifetime, the Earth is constantly changing over thousands or millions of years. And, likewise, all the lifeforms that inhabit Earth must constantly change to adapt to it. The animals we see alive today are the ones that are best adapted to the environment and ecology of the planet, the way it is right now.

There are several ways that species can become extinct. The most obvious one is when all the members of a species die out. This can happen for a lot of reasons: there can be a catastrophe, like when a meteor hit the Earth 65 million years ago and killed off the dinosaurs. There have been 5 times in the course of Earth's history when something major happened that killed off many, many species all around the planet. The biggest, called the end-Permian extinction, caused 95% of all species in the oceans to become extinct.

Species can also die out when other species compete with them for the same resources, and they lose, or when the environment changes and they don't adapt fast enough.

Its very,very rare, though, for a species to become extinct this way. The vast majority of extinct species we see in the fossil record became extinct when all of their members evolved into something new. All the species we have on Earth today evolved from similar-looking but different species that aren't around anymore. Different types of animals can evolve at different rates...for mammals, the average time a species can exist before it evolves into something else is about 1 million years. That means, in a million years, modern squirrels or rabbits may be extinct, but we may have another or even several new species of squirrel- or rabbit-like animals that descended from them.

In the museum, you can see many extinct species that are related to modern species. Mammoths and mastodons are similar to modern elephants, and all of them evolved from a common elephant-like ancestor. The giant Shasta ground sloth you can see is related to the smaller modern tree sloths, as well as two other types of giant ground sloths that were all adapted for living in different types of environments - forests, grasslands, and arid plains. Unfortunately for all of them, when the Ice Age ended and the environment changed, they couldnt adapt fast enough, and so went extinct.

DJ

Ask the Experts: What are the differences between mammoths and mastodons?

Mammoths and mastodons both fall within the taxonomic order Proboscidea, but they are classified in different families. Mastodons belong to the family Mammutidae, an extinct lineage, while mammoths belong to the same family as present day elephants, Elephantidae.

The key diagnostic difference between the two is the shape of their teeth, which helped them to eat different types of foliage. Mastodon means “breast tooth”, which refers to the pointed cusps on their molars that allowed them to crush leaves and other soft plant material. A forest ecosystem offered plenty of forage for the mastodons, such as Ponderosa pines, leafy trees such as oaks, Manzanita and other scrub plants. While mastodons had a leafy diet, mammoths primarily ate grass. The flat enamel plates of the mammoth’s molar were perfect for grinding up hard-to-digest grasses. Both dined well in the Domenigoni and Diamond valleys, with a rich buffet of grasslands, forests, and wetlands.

Another difference was that compared to mastodons, mammoths were taller and had longer, more slender limb bones, and higher, more rounded foreheads.

DH

Visitor Questions

Every week, we have hundreds of visitors coming through our museum here in Hemet, CA, to see our fascinating displays of Native American and 19th c. artifacts, and our amazing collection of Ice Age fossils, and a lot of these visitors ask us some really great questions about the archaeology and paleontology of Southern California. Periodically, our experts will answer some of our most popular questions for you here.

If you'd like to ask the experts a question, you can submit it via email to westerncenterblog@gmail.com, or better yet, come visit the museum and fill out a question card in our gallery.

Welcome!

Welcome to the Western Center for Archaeology and Paleontology Blog! The Western Center focuses on the rich archaeological and paleontological history of Riverside County with a wonderful collection of both Native American and historic artifacts, as well as the fossils from one of the largest ice age sites ever found. Here is the one place to stay up to date on exciting developments within the museum, from up-and-coming exhibits, education programs and field related news to the behind the scene activites of the Western Center Staff. Thank you for reading and please check back soon!