A sea turtle is perhaps the strongest aesthetic link we have to the time of the dinosaurs. The reptiles have been around for about 110 million years, and though birds are the only direct descendants of prehistoric dinosaurs today, turtles unquestionably satisfy the artistic vision we had of animals at that time; leathery, pockmarked skin, overlapping scale-like scutes, sharp beaks for shearing, and massive bulbous shells. This is because turtles actually were alive before dinosaurs were, and scientists estimate the basic design for the modern turtle was established some time in Triassic period. However, it is difficult to establish the concrete link between the animals we think of as dinosaurs, and with lizards, snakes, crocodiles, birds, and turtles.
Let’s just take a small break and explain exactly what dinosaurs are: dinosaurs are not anything and everything that lived in prehistoric times. They are, as defined by Margaret Dickinson on her (awesome) blog, “a member of the group that includes the most recent common ancestor of Iguanodon and Megolosaurus and all of that animal’s descendants.” This means that megalodon (yeah, the largest species of shark ever to have lived and one of the most powerful predators ever) is not a dinosaur, and neither are marine reptiles like mosasaur (the big one from Jurassic World), plesiosaurs, and yes, turtles. However, the definition (“descendants”) also means that birds are.
A recent DNA-sequencing endeavor by The California Academy of Sciences revealed a clearer picture of the turtle “tree of life” than ever before. By analyzing evolutionary relationships, the scientists found that turtles were more closely related to birds, crocodiles, and dinosaurs than lizards and snakes. These findings are interesting because they separate animals we once thought were all related under the “reptile” umbrella in to more distinct groups that are more true to their actual ancestry.
Does knowing the modern relatives of dinosaurs help us understand dinosaurs themselves? Extensive study by many paleontologists has revealed that most dinosaurs had feathers, or at least a primitive form of feathers called protofeathers. Some paleontologists believe that bird colour patterns can inform our understanding of dinosaur ones, and the University of Maryland’s Holtz said, “It seems reasonable to infer that the same size and shape melanosomes in dinosaurs would have resulted in the same colors as in modern birds.”
Dinosaur sound is another area that we know very little about. Since the structures for vocalization in animals are fleshy and do not fossilize, we do not know the sounds they made for sure. In Jurassic Park, dinosaurs have a complex array of chirps and bellows, and T-Rex would not be nearly as intimidating without its fearsome roar, but the sounds in the movies are usually a mash-up of various living animal sounds.
Knowing all this didn’t stop the rattling, wheezing sound that escaped the beak of one Loggerhead turtle that recently came into the aquarium from transporting me back to the time of the dinosaurs. The loggerhead, Daisy, was rescued by free divers on December 30th and weighed in at about 132 lbs. The rasping sounds she made were not intentional, but rather the product of her condition; one of her lungs was hyper-inflated due to a piece of metal lodged in her trachea, a CT scan she underwent revealed. Upon further inspection, this obstruction was found to be a large, rusting hook – probably from offshore longline fishing, a commercial fishing practice that frequently kills marine mammals and turtles as bycatch.
Daisy has since undergone surgery to remove the hook at Bermuda’s Kind Edward VII Memorial Hospital, a procedure that was new to both the hospital staff and the turtle. She is now in rehabilitation at the Bermuda Aquarium Museum and Zoo and under careful watch by the aquarium staff.
Daisy’s story is a remarkable one, and shows the extent to which humans can inflict damage upon and also help animals with our new technology. Daisy also provides a link between the dinosaurs and our own modern world by having a design constructed millions of years ago, and by having doctors understand and heal that design with the help of modern medicine. Her raspy breathing was obviously a manifestation of her condition, but the sound weaved her in to the picture of prehistory I have in my own imagination. Daisy unites past and present, and her story begs the question, what else will we be prompted to discover thanks to her?