[Biology Class Notes] on Difference Between Turtles and Tortoises Pdf [2024]

Tortoises and turtles belong to the same family called Chelonian or Testudines. The main thing that differs in both the reptiles is their habitat. Turtles dwell in water, whereas tortoises dwell on land. The main characteristic of both is the protective shell that is present as a defense mechanism for them. The limbs and head are protruding from the shell.

Turtles

Turtles are reptiles that dwell in America and Africa. The shell of a turtle is more streamlined and lighter compared to a tortoise. To help in swimming, turtles have long claws and webbed feet. Turtles come under the category of omnivorous animals, which means they eat both vegetation as well as meat. The average number of years of the life of the turtle is 20-40 whereas tortoises can live up to 86 years.

Turtles have a unique shell made of cartilage and bones. The shell acts as a protection or shield for the turtles.
They belong to the order Testudines. The Testudines include extinct and living species.
Middle Jurassic is one of the early known members from order Testudines. It means turtles belong to a group of reptiles, which are older compared to crocodiles or snakes.
Turtles are known as ectotherms or cold-blooded animals. The meaning of cold-blooded animals is that the internal temperature of the animal changes concerning the surrounding environment.
Because of the metabolic rates of sea turtles being high, the body temperature is more than the ambient water. Turtles come under amniotes, including other reptiles, mammals, and birds.
Turtles breathe air, and they do not lay eggs in water, just like other amniotes. The temperature is a significant factor in deciding whether the egg develops to a female or male.
The name turtle does not precisely say the taxonomical and biological distinctions of the species. The word indicates water-dwelling animals in the United Kingdom.
The leatherback sea turtle is the largest existing chelonian whose length can reach 200cm and weigh around 900kg. Turtles that live in freshwater are usually smaller in size, but few of the Asian softshell turtles can also reach 200 cm in length.
Turtles have two categories, based on how the retraction of their body parts back into the shell. In the Pleurodira suborder, the retraction of lateral is to the side and anterior to the shoulder girdles. Whereas in Cryptodira retraction is straight back, between the shoulder girdles.
The retraction movements depend on the morphology and the arrangement of the cervical vertebrae. In the recent species of turtles, there are nine joints and eight vertebrae in the cervical column, and they are independent.
The movement of the neck is flexible because there is no fusion of vertebrae, and vertebrae are round. This nature of the neck is evolved for eating or food consumption more than protection.
The hard outer shell of a turtle is known as a carapace. The inner part of the shell that covers the belly is called the plastron. Bridges are the bony structures that join the carapace and plastron. The shell has sharp scales known as scutes. A protein called keratin forms the scutes in turtles and also scales in other reptiles.
The shell of a turtle is usually brown, olive, or black. In some turtles, the green-colored shell is frequent. The shell often has markings, spots, or irregular surfaces.

Scientific Classification of Turtles

In general, we can define any animal in terms of its kingdom, phylum, class, clade, and order.
Turtles belong to the kingdom-Animalia, Phylum-Chordata, Class-Reptilia, Clade-Testudinata, Order-Testudines.
The subgroups are Cryptodira and Pleurodira. There are 14 living families with around 356 species.

Tortoises

Tortoises belong to the family Testudinidae and order Testudines. The main distinction between tortoises from turtles is the land habitat. Just like turtles, tortoises also have a protective shell, which protects them from predators and different threats.

The pectoral and pelvic girdles of a tortoise are within the rib cage, making them unique among vertebrates.
Tortoises are usually diurnal animals, and they tend to change temperature according to the ambiance.
Galapagos tortoises live up to 150 years, but the longest living tortoise named Adwaita is alive and about 255 years old.
Tortoises live in different habitats such as grasslands, deserts, wet evergreen forests, and also in mountain areas. Tortoises are usually found in southern North America, Mediterranean Euphoria, sub-Saharan Africa, and some islands.
Commonly, most of the species in tortoises lay small eggs and about 20 in number. Same as turtles, the carapace and plastron are the shell coverings in tortoises.
Just as the concentric rings on a cross-section of a tree can give an idea about the age of the tree, rings on the shell of a tortoise can sometimes be useful in the prediction of their ages. Tortoises have the longest living time compared to any other animals.
The typical way of predicting the sex of a tortoise is to analyze its tail. If the tail is small and dropped down, then the tortoise is a female; if the tail is longer and pulled up, then the tortoise is a male.
In many species of tortoise, the size of the femal
e tortoise is larger than that of the male. The plastron of male tortoises is curved to help in reproduction.
The period of incubation is usually long in many species. The average period ranges from 100 to 160 days. Tortoises lay eggs generally at night.

Scientific Classification of Tortoises

Tortoises belong to the kingdom-Animalia, Phylum-Chordata, Class-Reptilia,

Order-Testudines,Suborder-Cryptodira,Superfamily-Testudinoidea,family-Testudinidae

Difference between Tortoise and Turtle

Tortoise	Turtle
Tortoise belongs to reptiles, lives on land, and is a part of the family Chelonia.	Turtle belongs to reptiles, lives in water, and is a part of the family Chelonia.
They dwell in Africa and Asia. Some species of tortoise live in America.	They dwell in Africa and America.
Tortoises have large dome-shaped shells and have bumps on the shell in some species.	Turtles have streamlined and flat shells.
Tortoises have robust, heavy, and much rounded shells on their back.	Turtles have very light, thin and much-streamlined shells on their back
Their legs are not webbed, sturdy, and much larger to support their body weight	They have back feet that are webbed hence well equipped to be used underwater and front feet are paddle-shaped.
Generally, herbivores, but some species eat smaller beings.	Turtles eat both meat and vegetation, hence called omnivores.
Immediately after birth, the hatchlings of the tortoise shift from nest to mother tortoise’s burrow.	The hatchlings of a turtle live in the nest for around 90-120 days.
The lifespan of a tortoise is an average of 80-150 years. The longest a tortoise lives are 326 years.	The lifespan of a turtle is an average of 20-40 years. The longest a tortoise has lived is 86 years.
Tortoise are exclusively land animals who can reside in areas ranging from dry deserts to tropical forests	Turtles are water animals as they are well suited physically to live underwater, ut they go to land to lay their eggs

Conclusion

The main characteristic that easily differentiates turtles and tortoises is their dwelling. Turtles have shorter life spans compared to tortoises. Both the reptiles have protection on their bodies known as the shell. The shell of a tortoise is harder as they live on land and are subject to more harsh conditions. The scientific classification of turtles and tortoises is mostly the same.

Most people use the term “turtle” to refer to reptiles that are encased in a bony shell, but there are some differences between both these creatures even though they share the same root of the Testudines family. Here, we shall look at a few differences and some similarities between Tortoise and the Turtle.

Fun Facts about Tortoise and Turtles

Their shells are attached to their body, the inner layer of the shell is attached to the skeleton by ribs.
Both turtles and tortoises lack teeth and are well equipped with beaks. Turtles have sharp, ridged teeth as they are omnivores compared to tortoises as they have serrated-edged beaks.
Most of them don’t have a good hearing as their shells provide a high degree of protection from predators. Also, some turtles have good eyesight as well.
Both turtles and tortoises lay around 20-200 eggs in a patch of sand. But before they are hatched, they are eaten up by predators such as crows and raccoons. Even after they are hatched, their lives do not get any better as they are born without shells, they are gobbled up by various other species.