Turtles are somewhat archaic creatures; modern representatives of this group may need to be better distinguished from the turtles of the dinosaur era. However, turtles still need to evolve. In this article, we will tell you how they evolved.
Scientists divide all land vertebrates into three large groups: anapsids, diapsids and synapsids. Synapsids, which include mammals and ancient “zoo-eaters” (the ones we most often call synapsids), have only one temporal opening in the skull behind the eyes.
The diapsids, which include snakes, lizards, gaiters, crocodiles, birds and many of their extinct relatives, have two. Anapsids are characterized by the fact that their skulls do not have any occipital arches. Anapsids include Pareiasaurs, Procolophonus, and until recently included turtles. However, anapsids are now considered an invalid group.
In the first half of the XIX century, attempts have been made to find the closest turtle relatives.
At first, they included Sauropterygia (Sauropterygia) – a group of extinct lizards whose way of life was closely associated with water. Among them, some placodonts were exceptionally turtle-shaped. For example, Henodus (Henodus) from the Late Triassic of Germany not only had a flattened and osteodermal shell-covered body, but, like turtles, its teeth had disappeared.
Turtle drawing is interesting and exciting; the main thing is following our recommendations! But one scientific discovery has put an end to archaic notions. In 2013, paleontologists discovered one of the ancestors of turtles, Pappochelys. His discovery confirmed the ideas obtained through molecular phylogeny, bringing turtles closer to diapsids. It turned out that the “grandfather of turtles,” which is how it translates into Russian “pappochelys”, had two temporal openings behind the eyes. This means these holes were simply overgrown in his descendants, and turtles are not as “primitive” as previously thought.
Turtles appeared on the evolutionary scene at the end of the Triassic – about 220 million years ago. Some other groups of reptiles settled on our planet 130 million years earlier, but all of them, for various reasons, have been left behind by modernity. The reason for the geological longevity of turtles is seen in their excellent defence against enemies and ability to live in different conditions.
The immobility of the turtle torso, supported by only ten vertebrae, is compensated for by the flexibility of the cervical region. In most modern forms, it is a complex biomechanical structure that ensures that the head is quickly and smoothly retracted under the shell in moments of danger. The neck can bend zigzag horizontally or vertically, as in cryptodira (hidden neck).
However, there are species in which the cervical section is immobile, and the osteodermal shell is not developed. For example, they usually try to bite if they do not hide in time. By the way, all known turtles have lost their teeth, and in their place, there are sharp horny covers.
Let’s immediately start turtle drawing!
Turtle Drawing Easy
YOU’LL NEED:
- A piece of paper;
- a pencil;
- an eraser;
- patience;
- calmness;
- a good attitude;
Step 1
Tortoise body.
The turtle’s body is an oblong oval shape.
To make it easier to explain this to your child, invite him to draw an egg, which will then turn into a turtle.
During the creative process, you can interest your child by telling him that turtles, like birds, hatch from an egg.
Step 2
Shell.
The shell is an integral part of the turtle, without which its life is impossible. It performs a protective function and serves as a home for it. It covers almost the entire body of the animal.
Let’s separate the part for the shell with a semicircular line.
Step 3
Head.
Draw the turtle’s head under the shell. It is small and oval.
Step 4
Paws.
The turtle has four large but short legs. With their help, she overcomes long distances and digs shelters.
Step 5
Give the right shape.
For our turtle to have a more natural look, it must connect all body parts smoothly.
All unnecessary lines that intersect are erased.
Step 6
Parts of the shell.
Externally, the shell is divided into two parts, which a smooth line can visually separate.
The lower part of the shell differs from the upper part by the size of the horny shields. Draw one row from the bottom; the shields will be smaller.
The upper shields are slightly larger. They are arranged in a circle.
Toward the top of the shell, they gradually decrease in size.
Since the turtle uses its paws to move and dig shelters for itself, it needs sharp claws for this purpose.
Step 7
Skin cover.
The turtle’s skin looks rough and old, consisting of tiny “scales.”
Step 8
Eyes.
The turtle’s eyes are located on the sides and point downward.
Step 9
Outlines.
Erase any unnecessary outlines. Make the lines you want more straightforward by pressing the pencil down.
Step 10
Coloring.
We suggest giving the animal a more natural coloring.
Paint a dark green color between the shields on the shell.