Tag Archives: formation

What is paleontology

What questions fall within the purview of “Paleontology”?

Quite a wide variety, it turns out, because paleontology is the study of prehistoric life – the exploration of the entire history of life. Since 99.9% of all species that existed are now extinct, that is a lot of biodiversity. The science is multifaceted and diverse because the topic is equally diverse.

Because of the connections with geologic time and rock formations as the context of fossils, most paleontology classes are offered through geology programs at universities. I LIKE teaching introductory courses in geology because I find that people frequently end up taking geology in college as a last resort. Students generally are required to take a science class with a laboratory and they too frequently review their options without much enthusiasm. They took biology in high school and did not like it then, so want to stay away from that now. Chemistry and physics sound like a lot of math, so that leaves geology, they reason.

Fossil collecting in western Kansas. A partial mosasaur skeleton is visable in the middle foreground.

Fossil collecting in western Kansas. A partial mosasaur skeleton is visible in the middle foreground.

On the first day of geology class I like to point out that the study of the Earth and its history involves biology, chemistry, and physics, so we will cover them all. There is usually a little moan from the class at this, and I enjoy my moment of sadism. Paleontology in particular incorporates biology and geology to a very high degree, because to study fossils you have to fully understand the animals as well as the history that you can read from the rock record.

So could we come up with a classification, not of fossils, but of paleontologists?

Since the topic is so multifaceted the science falls naturally into several key areas. For example, individual paleontologists tend to be more oriented toward either geology or biology. The first group might be more interested in the animals themselves: how did they live; how did they move and capture prey; how did they relate to other organisms in their environment.

The second group might be more interested in what the animals can tell them about the Earth’s history: what do the fossils tell us about the movement of plates over the Earth’s surface through time; when did different animals live in geologic time so we can estimate the age of rocks; that sort of thing.

Of course, this is an over simplification.

Paleontologists can also be classified by which group of organisms they work with. Is it plants (maybe fossil forests made of ferns), or invertebrates animals — marine or terrestrial – ranging from the largest squid ever known to fossil spiders, or maybe vertebrate animals.

A lot of the people I know are paleontologists, and they tend to be people with diverse interests, often ending up doing a bit of all of it. For example, many years ago I worked on a fossil locality in southwestern Kansas that included plant, invertebrate, and vertebrate fossils. Having all the groups of organisms was critical to interpreting a much fuller picture of the ancient environment there than any one of the groups alone could have provided.

As a paleontologists I must be a “jack of all trades,” and that is one of the things I love most about it.

Other interesting facts can be found here at Boneblogger. Enjoy.

Bonnerichthys

In modern oceans, the very largest organisms specialize in filter feeding, or living on the very small plankton in the water. (Read more about the filter feeding niche). Up until now, it has appeared to researcher that during the Age of Dinosaurs, when the oceans were dominated by large, toothy reptiles, there were no marine animals specializing in the niche of large-bodied filter feeding, despite ample evidence that the oceans were rich in planktonic resources.

However, this niche was in fact filled during the Mesozoic as demonstrated in a recent paper in the journal Science (Friedman et al., 2010). Turns out that several species of fish did specialize in filter feeding, and they too grew quite large. Most of the specimens were already sitting in drawers in museums, having been misunderstood for many years, until Friedman and his colleagues re-evaluated them.

For example, one species has been known for over 100 years—having been named by E. D. Cope in 1873 as ‘Portheus’ gladius from a specimen collected from the Niobrara Chalk formation in western Kansas. The Niobrara Chalk was deposited during the Late Cretaceous period (see a geologic time scale). The species has a long and complex taxonomic history, mostly of interest to professionals, but it does clearly show that many scientists reviewed the fossil material and scratched their heads in wonder about this strange set of fossils.

Friedman and his colleagues have finally put the pieces together, and it fills in much about the history of life in the oceans. They have created a new genus in which to place the species, so now it is known as Bonnerichthys gladius. The genus was named for the Kansas fossil-collecting family that collected the most complete specimen found to date.

Bonnerichthys would have been about 20 to 25 feet in length with a huge, gaping mouth. You can see an artist’s reconstruction of Bonnerichthys at Oceans of Kansas. And you can listen to an interview with Matt Friedman at NPR.

This discovery opens up a whole new understanding of the paleoecology of the Mesozoic oceans, and shows that filter feeding was utilized for at least 100 million years longer as a major life strategy than previously recognized.

FRIEDMAN, M., K. SHIMADA, L. MARTIN, M. J. EVERHART, J. LISTON, A. MALTESE, AND M. TRIEBOLD. 2010. 100-million-year dynasty of giant planktivorous bony fishes in the Mesozoic seas. Science, 327:990-993.