Introduction to dinosaurs and bones!
Vocabulary:
Paleontology: the study of all prehistoric life.
Fossil: any preserved evidence left behind by a prehistoric organism.
Adaptations: traits that have been evolved because they serve specific purposes.
Content:
Dinosaurs came in all sorts of shapes and sizes! They weren’t all huge, some of them were probably less than a meter long when fully grown (like the Microraptor, or the Fruitadens)!! And, contrary to popular media (The Jurassic Park series), the Velociraptor was actually about the size of a dog, or a turkey; give or take.
A good example of an adaptation would be bones! Bones help all animals survive by serving four major functions:
They passively resist the force of gravity and maintain an animal's form!
Bones provide a rigid framework for muscle attachment!
As much as they provide protection internally, they could easily be fantastic weapons (think horns, and other things like that).
They act as HUGE mineral reserves!
The Skulls and Jaws!
Vocabulary:
Vertebrates: animals with two kinds of special skeletal adaptations: the skull and vertebrae.
Vertebrae: structures primarily made out of bone and/or cartilage that surround a portion of the spinal nerve cord.
Vertebral column: a series of interlocking vertebrae.
Brain case: a hollow chamber formed by multiple skull bones that houses the brain!
Fenestrae: Latin for “windows.”
Content:
Skulls are not singular bones! The skull is made up of many bones that are tightly locked together. The skull itself can give greater insights about a dinosaur's life than really any other bone(s)!
The upper and lower jaws may contain teeth and/or include a beak, and these things are critical for paleontologists to be able to interpret what the mighty beast(s) were adapted to eat!
The rear portion of the skull includes the brain case. There are many small openings in the brain case that allow nerves to connect to the brain. Which is very important, and is still a present adaptation today. The size and shape of the brain case can indicate the size and/or shape of the brain it housed, and, therefore, provides us with clues to the dinosaur's mental capabilities!
Dinosaur skulls also have multiple pairs of large openings! These included the:
Nares: the openings for the nostrils.
Orbits: the openings for the eyes.
In some modern animals, like turtles, there are no other skull openings. This is another example of animals evolving and adapting to their environments! Dinosaurs had a few more openings in their skulls, which were called:
Fenestrae!
Behind each orbit there were two fenestrae:
On the lateral sides of the skull, there were the two laterotemporal fenestrae.
On the top of the skull, there were the two supratemporal fenestrae.
Both pairs were present in the skull to make room for large jaw muscles!
Between each orbit and naris, dinosaurs also had a third pair of fenestrae! These were called the antorbital fenestrae. Though, the exact function of this is unclear; I like to think that in some dinosaurs it helped warm the air that they breathed, and in others it simply made the skull a little bit lighter.
