A preserved turtle Skeleton showing how the plastron and carapace connect to form a complete shell covering the whole body. skeletal elements (right) and flippers (left), both parts of the turtle’s upper shell. Note the difference in the sizes of the flippers on a turtle with a tail and on one without a tail.
A turtle skeleton must be well preserved in order to be examined by scientists. The quality of its preservation depends on many factors. These include; the thickness of the shell, how it was buried, and whether or not the turtle died of natural causes or was preserved using tissue preservation or by artificial means. The thickness of a turtle shell depends on two factors, the total volume of the shell and the weight of the entire animal. The thickness of the shell is inversely proportional to the age of the turtle. For example, a turtle mature at the age of twelve years would have thick flippers, compared to a turtle mature at the age of fifteen years that would have thin flippers.
Another important factor in determining the quality of turtle skeletons is their geographic location. A well-preserved sea turtle skeleton will give a good enough description of its genus and species, to enable us to differentiate them from other Sea Turtles. The most prominent taxonomic division among Sea Turtles is the Phylogenidae which consists of eighty different subspecies. These turtles are widespread in all the oceans of the world except the Cretaceous.
A well preserved turtle skeleton will give enough details concerning the size, color, and color patterning of various bones and soft tissues present in it. These include the options (bones that constitute the lower jaw), jaws, claws, scales (covering the head), palate (the covering that protects the soft brain and respiratory organs), and holnose (which encloses the upper digestive tract). These parts of the turtle body need to be well preserved because they are crucial for proper identification. For example, the presence of pleurocytes (plural of “pleura”) is an indicator of a fully-developed nervous system, and the presence of antlers (which grow in the rear part of the neck) provides evidence for the feed behavior of this animal.
220 million years ago, a small group of dinosaurs known as oviraptorids got their first chance to walk the earth when the Chicops came out of the sea. Their ancestors had evolved into more gigantic creatures called Ordoviridae, but when these dinosaurs became small, they began walking using their toe claws. It is believed that these tiny creatures used their footie legs to walk on the rocky surfaces of what is now known as the Teperinos Mountains.
The fossil record shows us that these tiny creatures were walking upright until the Paleocene era. Some time later, their population started to decrease because of massive volcanic eruptions. In order to conserve their population, these dinosaurs must have been able to increase their numbers by means of something other than migration. They may have borrowed or taken over the carcasses of other organisms like birds, and using them as their personal shells. The most plausible suggestion for this phenomenon is that these creatures used their feathery bodies as a means of making a very comfortable home for themselves.
The appearance of turtles’ skeleton gives us another clue as to the manner in which they covered their lower parts. Their limbs were protected by their thick plastrons (plural of “plastron” is Latin for “wing”). Plastrons are long, thin, and flexible cords which are used in the transportation of food between the lower intestine and the stomach. Their construction enables them to hold the tail of the turtle and to provide much needed friction between limbs. The presence of these plastrons also indicates that turtles fed on both meat and eggs.
Another clue we can draw from the fossil record concerning the manner in which turtles evolved is that these animals also evolved into wingless creatures. During the Cretaceous geological period, millions of decades before the inception of humans, turtles had evolved into wingless adults by the use of their wings. Their forelimbs were constructed much like a fin, and their body was highly specialized for generating propelling force through flapping of its wings. Evidence of such flapping can be found in the form of teeth and other indicators of wing membranes.
A third clue which proves that turtles really did evolve into winged beings is that their forelimb and hindlimb bones are different in shape and size from one another. Although the complete ribs of a turtle are very similar to the shape and size of the talons and digits of modern birds, the presence of numerous ridges on the back of each bone shows that these creatures used their claws for driving themselves about on land rather than swimming. This is not to say, however, that all turtles followed this course of action. Through the Eocene era, the first traces of arboreal life can be seen in the form of hooflike flapping feet on the lower jaws of these prehistoric creatures.
The most definitive evidence of turtle evolution is found in the form of the posterior carapace, or plastron, of the turtle. Constructed out of soft-plastic, stiffened tissue, this plastron is the innermost part of the turtle’s shell. The plastron is held together by two pairs of pleats which are connected by means of an opening in the middle. In addition to its role in housing the spinal cord and nerves, the plastron also serves to protect the turtle’s vulnerable eyes, limbs, head, and tail from the elements. The presence of teeth within the mouth of these creatures provides further evidence of their pre-mammal lifestyle.
From the time of the earliest known reptile, the split-open jaws of dinosaurs indicate a lifestyle that was much more complex than the one portrayed in today’s popular films and books. In fact, it is estimated that dinosaurs used their shells as weapons and probably attacked their prey using their claws. Exactly how turtles developed their sophisticated chewing and swallowing capabilities remains unclear, but many speculate that the evolution of turtles might have followed the same path as that of rodents. Through the Eocene era, these prehistoric creatures began developing their teeth and jaws much like those of modern-day elephants and cheetahs. With the addition of chelicosaurid ancestors to the family tree of turtles, the origin of turtle culture came into being.
