I went to the Tyrannosaurs – Meet the Family exhibition at Scienceworks Museum recently and learnt a few interesting things.
T. rex is the most famous family member – but as you might have guessed it had many tyrannosaur relatives – the group is called the Tyrannosauroids. One of the cool digital exhibits is a hands-on virtual family tree, where you can try and fit the different species of tyrannosaur into their position. Scientists call these family trees phylogenetic trees and they show how each group of dinosaurs arose from another (1).
The thing I found most fascinating was how scientists have been able to work out what colour the feathers of a dinosaur called Anchiornis huxleyi were likely to have been! The study was published in the journal Science and used a very high powered microscope (scanning electron microscope) to find out what pigments were in the fossil feathers. The shapes of tiny structures (melanosomes) in the feathers were compared to the equivalent structures in feathers of living birds. The paper’s authors worked out that the dinosaur was probably grey with red head plumage and face speckles, and had white and black forelimbs. (It blows my mind that this level of microscopic detail is still there in the 155 million year old fossilised feathers!!) Some say these shapes might just be bacteria. What do you think? These structures have distinct patterns of distribution like stripes on the wings so I prefer the colour explanation.
Did you know some dinosaurs had feathers? Many of the coelurosaurs did – including two tyrannosaurs: Dilong and Yutyrannus. (You can see a Dilong at the Scienceworks exhibit.) Birds have now been put on the dinosaur family tree, in the coelurosaurian theropod branch along with the tyrannosaurs – so they’re “cousins”! Did T. rex have feathers? Maybe…. We won’t know until someone finds a fossil T. rex with feathers.
As for the dinosaur’s roar – you hear it in pretty much any dinosaur documentary or movie.
What noise did T. rex actually make? We don’t know. The roar is just a creative guess.
For more information read below!
(1) Phylogeny is the science of working out how different species are related from various clues. The best clues for dinosaur phylogeny come from comparing body features revealed by fossils. Knowing how old the fossils are helps too – the older fossils came before the younger ones. A phylogenetic tree is the best guess, and sometimes evidence comes up that changes what the best guess is. Birds weren’t put on the dinosaur phylogenetic tree until the late 20th century, after more and more evidence was found. DNA can provide pretty good clues for phylogeny, because the species that have more similar DNA are probably more closely related. We don’t have DNA from dinosaurs BUT a rare find of preserved T. rex protein has been reported and its analysis supports the relationship with birds.
(2) Notice how I’ve written scientific dinosaur names? All species are given a scientific name made of a genus (Tyrannosaurus – it can be shortened to the first letter – T. but notice that the first letter is always in upper case) and species (rex – all lower case).
(3) David Weishampel has reconstructed the big air spaces and tubes of a hadrosaur to try and recreate the sound they might have made – you can hear the sound being recreated here: