Paleobiology on EARTH Magazine

Frogs fill in post-Gondwana picture

Wed, 13 Feb 2019 16:29:47 -0500

Land connections, bridges and corridors may have enabled the dispersal of plants and animals, including frogs, among the landmasses around the Indian Ocean after the breakup of Gondwana. Credit: Seshadri.K.S., CC BY-SA 3.0

The positions of landmasses after the breakup of Gondwana during the late Mesozoic and early Paleogene are highly debated, especially the configurations of the Indian and Australian plates around the newly opening Indian Ocean. In a new study, the paleogeographic and genetic distributions of a group of frogs called Natatanurans were used to test the various post-breakup models — and the results bring additional clarity to the post-Gondwana puzzle.

Dinosaur soft tissues preserved as polymers

Wed, 13 Feb 2019 16:05:07 -0500

Since 2005, several samples of ostensibly soft tissue, such as blood vessels and bits of organic bone material, have been gleaned from dinosaur bones. The finds have stirred debate because the notion that intact dinosaur proteins could survive tens of millions of years has proved a tantalizing but difficult pill to swallow for many paleontologists. In a new study, however, researchers have identified a chemical pathway — well known in food science but not seen before in paleontology — that may be the key to long-term preservation of soft-tissue structures.

Marine animals have been migrating for millions of years

Tue, 16 Oct 2018 09:46:47 -0400

Marine organisms like corals, sponges and snails have been migrating for millions of years, mostly driven by temperature changes. Credit: Carl Reddin.

Scientists have suspected that ancient animals migrated in response to changing global temperatures, but until now, there was no documentation of this across extensive time periods. In a new study, researchers found that, for millions of years, marine organisms like corals, sponges and snails, have shifted their ranges in response to climate change.

Down to Earth With: Paleobiologist Rowan Lockwood

Tue, 03 Jul 2018 10:39:57 -0400

Rowan Lockwood, a professor of paleobiology in the Department of Geology at the College of William and Mary in Virginia, studies ecological changes through geologic time to inform modern conservation approaches. Credit: Stephen Salpukas.

In 1608, Captain John Smith noted that oysters “lay as thick as stones” on the floor of the Chesapeake Bay. The shell reefs — built up by hundreds of years of oyster generations — were so large, ships wrecked against them. And each oyster was so massive, to eat one, you had to cut it into pieces — like a steak.

Fossil sea turtle hatchling reveals its Eocene proteins

Fri, 12 Jan 2018 14:37:45 -0500

Preserved biomolecules were found in this specimen of an Eocene sea turtle, Tasbacka danica, which was found in Denmark. The circle in (b) indicates the part of the turtle's carapace — enlarged in (c) — sampled by researchers. Credit: Lindgren et al., Scientific Reports, October 2017, CC BY 4.0.

A study of a 54-million-year-old sea turtle hatchling found in Denmark is adding to a growing body of evidence that certain proteins can remain intact in the fossil record for tens of millions of years.

Down to Earth With: Paleobiologist Gregory Erickson

Mon, 18 Sep 2017 14:37:02 -0400

Gregory Erickson is a professor of anatomy and vertebrate paleobiology at Florida State University in Tallahassee, Fla. Credit: Gregory Erickson.

As an undergraduate at the University of Washington, Gregory Erickson wasn’t sure what he wanted to do. He started out as an engineering major, then dabbled with getting a degree in wildlife management. In 1986, having taken numerous science courses, he happened to compare notes with his best friend, a geology major, and realized he was just a few courses shy of obtaining a geology degree himself. Eager to finish college, Erickson signed up for a class in vertebrate paleontology focusing on dinosaurs — a decision that ultimately changed his life.

Down to Earth With: Paleobiologist Nigel Hughes

Thu, 12 Nov 2015 10:53:48 -0500

Nigel Hughes in Bengal. Credit: Nigel Hughes.

I first met Nigel Hughes, a paleobiologist at the University of California at Riverside (UCR), in 2010. He took me on a brisk walk through the UCR Botanical Gardens, where the trees kept us cool in the hot Southern California sun while he told me all about trilobites.

Early Triassic fossil showed live birth in action

Mon, 23 Jun 2014 11:13:10 -0400

A young Chaohusaurus, a marine reptile that lived about 248 million years ago, is seen emerging headfirst from its mother in this portion of a remarkably preserved fossil. The head of a second juvenile, still inside the mother, is also visible to the left. Credit: ©Ryosuke Motani, CC-BY 3.0 US.

Not only does the fossil specimen preserve an example of live birth, or viviparity, in action, but the embryos are about 10 million years older than previously preserved embryos of Mesozoic marine reptiles, reported Ryosuke Motani of the University of California at Davis and his colleagues in PLOS ONE. Additionally, the headfirst birth posture — characteristic of births in most viviparous terrestrial animals — suggests that marine reptiles, which are known to have evolved from terrestrial reptiles, inherited viviparity from these land-dwelling ancestors, the researchers wrote. This contrasts with the conventional view that live birth evolved in marine reptiles as an adaptation to life in the sea, and further suggests that terrestrial reptiles evolved the trait much earlier than previously thought, they noted.

Did tidal zone trilobites lead the way onto land?

Mon, 23 Jun 2014 10:52:13 -0400

Artist's rendering of trilobites on an Early Cambrian tidal flat. Trilobites first appeared about 520 million years ago and thrived for 270 million years until the end-Permian extinction, making them one of the most successful lineages to ever live. Kathleen Cantner, AGI.

During the Cambrian, when trilobites thrived in Earth’s early oceans, the continents were devoid of animal life. “The Cambrian explosion was an open marine event,” says Gabriela Mángano, a geologist at the University of Saskatchewan in Saskatoon, and lead author of the new study, published in Geology. “The typical story is that colonization of the terrestrial settings didn’t happen until the middle of the Paleozoic with organisms moving from the sea, into brackish water, then freshwater and then onto land.”

The trouble with turtles: Paleontology at a crossroads

Wed, 19 Mar 2014 11:15:51 -0400

Scientists debate whether modern turtles are more closely related to snakes and lizards or birds and crocodiles.

Traditional paleontological research has been upended over the past few decades, as less traditional fields, such as genomics and developmental biology, have weighed in on vertebrate evolution. Researchers have examined the lingering color elements in dinosaur feathers, the genetics of woolly mammoths, purported proteins and blood from dinosaurs, and other ancient fossil signatures using modern tools. But the question of turtle evolution has remained resistant to both traditional and novel methods.

CSI La Brea: Tiny traces reveal big secrets of the tar pits

Tue, 15 Oct 2013 11:11:47 -0400

Kathleen Cantner, AGI

The La Brea tar pits in the middle of Los Angeles are known for turning up spectacularly preserved specimens of dire wolves, saber-tooth cats and woolly mammoths. But how long it took for the animals to sink down into the sticky tar after they became trapped has long been a mystery. Now a new study looking at the traces left by hungry bone-eating insects is providing a minimum time span for burial, as well as confirming some long-held suspicions about when the tar pits were at their most lethal.

Bringing dinosaur biology into the 21st century

Fri, 06 Jul 2012 15:59:04 -0400

Skeleton of the _Giraffatitan brancai_ at the Museum für Naturkunde in Berlin, Germany. This is the largest mounted dinosaur skeleton in the world. Axel Mauruszat

Meike Köhler and colleagues looked at rest lines in the bones of modern ruminants like the _Muntiacus _deer to compare them to rest lines in dinosaurs. Courtesy of Meike Köhler

We may know a lot about dinosaurs, but there’s an awful lot we don’t know yet, especially about their biology. How heavy were the dinosaurs? Were they fast or slow? Recent research poses new answers to these long-standing questions.