Researchers have discovered what dinosaurs would look like under a microscope by comparing the genomic structures of the extinct animal's closest living relatives.
Genome Structure Of Dinosaurs
Birds and turtles may not look anything close to a tyrannosaurus, but these animals are the closest thing researchers have to understand dinosaurs.
By looking into the genome structures of birds and turtles, a team of researchers at the University of Kent were able to map out the overall genome structure of dinosaurs, including everyone's favorites, the tyrannosaurus rex and velociraptor.
Genome structures are also called karyotypes. They are composed of chromosomes, or the thread-like structures found in cells that carry a living organism's DNA.
The researchers found that the genome structure of dinosaurs is similar to that of their modern-day descendants.
Finding A Common Ancestor
The study, which was carried out in the laboratory of Darren Griffin, professor of genetics at the School of Biosciences of the University of Kent, involved comparing how the chromosomes of birds and turtles were organized. Details are published in the Nature Communications journal.
The researchers traced their genome structures to a common ancestor, an ancient lizard-like animal that lived 260 million years ago. This is some 20 million years before the first dinosaurs emerged during the Mesozoic Era.
The researchers then mapped out how the genome structure evolved over the course of hundreds of millions of years and found that the dinosaurs came from the same evolutionary branch, meaning they have a similar karyotype to present-day birds.
"This lineage includes the emergence of dinosaurs and pterosaurs 240 million years ago, passing through the theropod dinosaurs (whose members include T.rex and Velociraptor) and ends with birds," Griffin and coauthor Rebecca O'Connor say in an op-ed piece written for The Conversation.
Modern-Day Descendants
The researchers say that although individual chromosomes rearranged themselves internally, the re-organization did not occur between chromosomes. Birds and dinosaurs also have many chromosomes, which may explain the diversity of both species.
The study suggests that the chromosomes of dinosaurs are not at all unlike that of birds. In fact, if modern-day scientists were able to examine a dinosaur's chromosome under a microscope, it would not look any different from that of a duck, a chicken, or an ostrich.
The particular arrangement of chromosomes has remained the same throughout hundreds of millions of years, meaning this karyotype most likely carries out functions critical to the survival of birds and dinosaurs.
"That conservation, to me, is remarkable," says Nicole Valenzuela, coauthor and professor of ecology and evolution at the Iowa State University. "Things are usually conserved over that scale of time because they're important."
The researchers used a set of fluorescent probes used for birds to illuminate the genome structure of turtles.
