As we know, within the era of Mesozoic There are 3 periods that mark differences in the development of both flora and fauna and climate and geology. Those 3 periods are: Triassic, Jurassic y Cretaceous. Today we are going to focus on studying the Jurassic fauna. This is the period when all dinosaurs spread through most of the tropical areas of the planet.
In this article we are going to tell you everything you need to know about the development of the Jurassic fauna.
Key features
If there was one thing that stood out about the Jurassic Period, it was the consolidation of a vast development of life, both in plants and animals. During the 56 million years that this period lasted, all plants were able to create jungles and forests in which a large number of animals flourished.
Among these animals that make up the fauna we find dinosaurs. The animals that predominated in all landscapes were both terrestrial and aquatic environments. We must not forget that during this period at the geological level there was an intense activity of the tectonic plates.
Dinosaurs were the best-known animals thanks to the extensive study they have received from the fossils that have been recovered. Animal life during this period was able to conquer all habitats, both terrestrial, marine, and aerial. To learn more about the period, you can consult the article on the .
Development of the Jurassic fauna
invertebrates
Within the invertebrate group, we can see that mollusks predominated. Among the mollusks, it was the gastropods, bivalves, and cephalopods that expanded and diversified the most. Due to an extinction that occurred during the late Triassic Some classes became extinct, such as the Ammonoids and Nautiloids. (persist to this day) and Belemnoideos.
Another group of invertebrates that also experienced significant diversification during the Jurassic were the echinoderms. Within the echinoderms, those belonging to the asteroid class were the most widespread. Starfish are included in this class. Echinoids populated a large number of marine habitats. Sea urchins are included in this group.
Throughout the period arthropods abounded. Mainly all those belonging to the class of crustaceans were developed in the marine environment, in which we have crabs. In addition, there were some specimens of insects such as butterflies, wasps and grasshoppers.
Vertebrates
As expected, among vertebrates, the reptiles completely dominated this period. Of the Jurassic fauna, the dinosaurs were the most predominant group of animals. Amphibians also began to stand out, but to a lesser extent. Although there were few representatives of the mammal group, they too began to develop during this period.
In aquatic habitats we find ecosystems teeming with life. Most of the life that existed at that time was developed in the marine environment. There was a great variety of fish, although aquatic reptiles were the kings of the water. The most representative are the following:
- Ichthyosaurs: This reptile species was distributed throughout the world's seas. Its diet was entirely carnivorous, attacking large prey. They could measure up to 18 meters in length and had several fins, one caudal and one dorsal. Their morphology includes an elongated body and a long snout, which served to better grasp prey. Their environments were highly developed for effective tearing. Based on the fossils found of ichthyosaurs, we can deduce that they were viviparous animals. That is, the embryo develops inside the mother's body.
- Plesiosaurs: These marine animals were larger than ichthyosaurs. They could measure up to 23 meters in length. Their necks were extremely long. They had four limbs that allowed them to move faster underwater and were shaped like flippers. Their bodies were quite wide.
Jurassic fauna of the aerial and terrestrial type
Let's not forget that small birds also appeared during the Jurassic period, although flying reptiles ruled the air. These were the pterosaurs. These animals ranged in size depending on the species, and we could find them from tiny to enormous. Their bodies were covered in hair and they had long wings formed by a membrane that hooked onto the fingers, similar to those of bats.
Thanks to the numerous fossils that we found of the Pterosaurs we can know that they were oviparous. It has been possible to deduce that they had a good view to be able to capture prey from the heights. This is because their diet was fully carnivorous and they could also feed on fish and some insects. In order to catch fish that are in the water they need a good view.
As for terrestrial vertebrates, we have mainly the large dinosaurs. Dinosaurs existed in two types: carnivores and herbivores. Among the herbivores, the Apatosaurus, Brachiosaurus, Giganotosaurus, and Camarasaurids predominated. Let's briefly describe them:
- Apatosaurus: It can weigh up to 30 tons and was large (21 meters).
- Brachiosaurus: It walked on 4 legs and was characterized by its large size and long neck. It was 13 meters high and 23 meters long.
- Camarasaurus: It could grow up to 18 meters in length. Its spinal vertebrae had a kind of air chamber that served to reduce its body weight.
- Gigantspinosaurus: It was completely armored with bony plates. Although it wasn't that big, it offered great protection. It could reach 5 meters in length.
Among the carnivorous dinosaurs we have the following:
- Allosaurus: on their extremities they had sufficiently developed claws to be able to capture their prey. They could measure up to 12 meters in length.
- Compsognathus: Although it was carnivorous, it was extremely small, reaching only one meter in length.
- Cryolophosaurus: It reached only 6 meters in length and 3 meters in height. Its front limbs had strong claws capable of tearing its prey to pieces.
I hope that with this information you can learn more about the fauna of the Jurassic.