Fossil Friday – horse molar


As we continue to work on WSC’s collection of Late Pleistocene fossils from Murrieta, it has become clear that, while the collection my be taxonomically diverse, it contains a lot of horse bones! Continue reading


Fossil Friday – freshwater snail

IMG_2137The world of the dinosaurs was populated by some of the most gargantuan and charismatic animals ever to roam our planet. It is easy to forget that the Mesozoic Era was just as rich with all sorts of life as our modern world. Continue reading

Fossil Friday -crocodilian teeth


Tyrannosaurs were not the only large reptilian predators prowling through North America in the Late Cretaceous Epoch. Crocodilians made rivers and lakes dangerous places to linger, even for small dinosaurs. Unlike today, with American alligators and crocodiles found only in the Southeast, during the Late Cretaceous crocodilians lived all over North America. Continue reading

Fossil Friday – horse lunate

We’re continuing our efforts to document an describe the fauna from the Harveston neighborhood of Murrieta, a small but diverse collection that appears to be the only Rancholabrean-Age site in Murrieta. Continue reading

Fossil Friday – lizard vertebra

Although the name Dinosauria means “terrible lizards”, the dinosaurs are not lizards at all, but instead are their own separate group of reptiles (the “terrible” part depends on whom you ask). Even so, there were actual big lizards living alongside the dinosaurs during the Cretaceous Period. Continue reading

Fossil Friday – Smilodon femur

Carnivores make up a relatively small percentage of any stable ecosystem; the principle of Conservation of Mass and Energy really doesn’t allow for any other possibility. As a result, carnivores generally make up a tiny percentage of the fossils found in most deposits (although there are exceptions, such as predator traps like Rancho La Brea). Nevertheless, sometimes paleontologists get lucky and carnivores turn up in herbivore-dominated deposits. Continue reading

Fossil Friday – ray tooth

IMG_1955We usually think of rays as creatures of the ocean. However, these flattened cartilaginous relatives of sharks also inhabit freshwater, and include the striking freshwater stingrays of South America and the giant freshwater stingrays of southeast Asia. During the Late Cretaceous Epoch, freshwater rays also prowled the waterways of North America. Continue reading

Fossil Friday – possible Leptoceratops tooth

If you follow the Western Science Center on social media, you have probably noticed that horned dinosaur fever has gripped the museum. We are gearing up for the March 24 opening of “Great Wonders: The Horned Dinosaurs”, a new exhibit dedicated to the ceratopsians. The most famous ceratopsian must be Triceratops. Triceratops lived at the very end of the age of dinosaurs, right up to the mass extinction that wiped out all the dinosaurs (except modern birds) 66 million years ago. Continue reading

Fossil Friday – horse mandible

We’re continuing our review of our collection of Pleistocene fossils from the Harveston neighborhood of Murrieta, in southwestern Riverside County. This is a diverse fauna with a number of different genera, but it appears that in terms of shear numbers of bones this collection is dominated by horses. Continue reading

Fossil Friday – strange mastodon vertebrae

A lot of the work done by paleontologists and biologists, especially those that work on taxonomy and systematics, is trying to identify general characteristics that various groups of animals have in common and that differ in other groups. The characters are the raw material that we use to define and identify species, to unravel the evolutionary relationships between those species and group them into higher taxa, and to identify sexes, ages, and other features. But, of course, the smallest unit we deal with is the individual animal, and sometimes fossils are emphatically, stubbornly individualistic. Continue reading