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How and why to date a dinosaur

You might think dating dinosaurs would be an easy task, but in reality it’s actually quite difficult. We date dinosaurs based on where we find their fossils, using the ages of the rocks that they’re found in. This means that the ‘ages’ of different dinosaurs is actually indirect and constrained by how well we’re able to date the rocks they were found in.                               

As well as this, we know that the occurrences of dinosaur fossils are not accurate representations of their age either. If we know one dinosaur species A was around 120 million years ago, and its closest relative species B known only 100 million years ago, then species B must have existed 120 million years earlier too as they must have shared an origination time due to the way speciation works – we just haven’t found any fossils of it during this 20 million year gap though. And we call these ghost ranges or lineages.

What these ghost ranges do, when combined with trees that illustrate the relationships between different organisms, is alter the timings or dates of important events based on exactly how we time-scale the trees and the ghost and true ranges of species.

This uncertainty in dating and the methods we use actually has quite important implications for significant events in the evolutionary history of dinosaurs.

“I would like to humanize the space age by giving a perspective from a non-astronaut, because I think the students will look at that and say, ‘This is an ordinary person. This ordinary person is contributing to history.’”

usatoday

Thirty years ago today, the space shuttle Challenger blasted off at 11:38 a.m. ET. Then, 73 seconds after liftoff, a fireball engulfed the shuttle. As a horrified America watched on live TV, the orbiter broke apart, dooming its crew of seven, including high school teacher Christa McAuliffe, third from right, who was supposed to become the first civilian in space. 

These Crazy Cute Baby Turtles Want Their Lake Back

California’s First Documented Wolf Pack Recorded in Siskiyou County

by David Smith / The Siskiyou Daily News California’s first pack of wolves has been documented by the California Department of Fish and Wildlife and the United States Fish and Wildlife Service. USFWS Wildlife Branch Chief Eric Loft opened a media conference call on Thursday by stating, “We’re really excited, if not amazed, by what this animal can do.” He stated that the rapid colonization of the…