Jurassic Period
Jurassic Period
The Jurassic period is the second of the three divisions of the Mesozoic era, "The Age of Reptiles." The Jurassic lasted for 64 million years, from about 208 to 144 million years ago.
Climatic Changes:
Widespread deposits of sand in western North America indicate that the region experienced a desert climate during the early Jurassic. Coral reefs and the remains of temperate and subtropical forests around the world provide evidence that the climate became moister and milder later in the period. Europe was covered with shallow seas throughout the Jurassic.
Vegetation:
Jurassic vegetation consisted mainly of seed ferns, cycads, horsetails, conifers, and gingkoes. The Jurassic is sometimes called the "Age of Cycads" because of the variety and diversity of these seed-bearing, palmlike plants. Some cycads grew to be tall as trees; other forms were short and squat.
Marine life: Marine life of the Jurassic Period was also highly diversified. The largest marine carnivores were the Plesiosaurs. These carnivorous marine reptiles typically had broad bodies and long necks with four flipper shaped limbs. Ichthyosaurus was a more fish-shaped reptile that was most common in the early Jurassic. Because some fossils have been found with smaller individuals that appear to have been inside the larger ones it is hypothesized that these animals may have been among the first to have internal gestation and bear live young. Among the most beautiful fossils of marine life were left by the spiral shells of the Ammonites.
Age of Dinosaurs:
The Jurassic period is known for an increase in the numbers and diversity of dinosaurs. At the beginning of the period, dinosaurs such as the bipedal and carnivorous theropods were small and lightly boned, feeding on insects or other small dinosaurs. By the close of the period, massive predators like Allosaurus and Ceratosaurus had appeared. These dinosaurs had heavy bodies, powerful hind legs,
The Jurassic period is the second of the three divisions of the Mesozoic era, "The Age of Reptiles." The Jurassic lasted for 64 million years, from about 208 to 144 million years ago.
Climatic Changes:
Widespread deposits of sand in western North America indicate that the region experienced a desert climate during the early Jurassic. Coral reefs and the remains of temperate and subtropical forests around the world provide evidence that the climate became moister and milder later in the period. Europe was covered with shallow seas throughout the Jurassic.
Vegetation:
Jurassic vegetation consisted mainly of seed ferns, cycads, horsetails, conifers, and gingkoes. The Jurassic is sometimes called the "Age of Cycads" because of the variety and diversity of these seed-bearing, palmlike plants. Some cycads grew to be tall as trees; other forms were short and squat.
Marine life: Marine life of the Jurassic Period was also highly diversified. The largest marine carnivores were the Plesiosaurs. These carnivorous marine reptiles typically had broad bodies and long necks with four flipper shaped limbs. Ichthyosaurus was a more fish-shaped reptile that was most common in the early Jurassic. Because some fossils have been found with smaller individuals that appear to have been inside the larger ones it is hypothesized that these animals may have been among the first to have internal gestation and bear live young. Among the most beautiful fossils of marine life were left by the spiral shells of the Ammonites.
Age of Dinosaurs:
The Jurassic period is known for an increase in the numbers and diversity of dinosaurs. At the beginning of the period, dinosaurs such as the bipedal and carnivorous theropods were small and lightly boned, feeding on insects or other small dinosaurs. By the close of the period, massive predators like Allosaurus and Ceratosaurus had appeared. These dinosaurs had heavy bodies, powerful hind legs,