Evolution of Crocodiles

Evolution of Crocodiles

Adaptations

Anatomical:

• Anatomical
• Palatal- valve at the back of their throat to stop water from getting in
• Stomach- can dissolve anything they consume due to their eating habits
• Scales- provide good camouflage along with their color

Physiological

Behavioral

• Eggs: They lay their eggs in nests above the water so they don't flood, but in order for them not to dry out, they lay them during the wet seasons
• Eating: They eat stones to balance their digestive system
• Basking and Sunbathing: They bask to cool themselves down and sunbathe to keep warm when cold

• Acidic Stomach: They have the highest acidity out of all vertebrates, which allows them to easily digest their food
• Metabolism: They are able to regulate their own metabolism, so when their environment is a good temperature for them, they can slow their metabolism so food is not necessary every day

Modern Relatives

• Alligator:
• Tough skin due to thick vegetation
• Webbed feet for aquatic environments
• Teeth can regrow
• nostrils on the top for swimming

By: Kadienne Sizemore & Blu Funk

Period 6

Environment

• the Protosuchus was more suited for land with longer legs and eyes on top of its head. Though it was drove into water by competition with early dinosaurs
• -this caused the marine reptile Mesosuchia to evolve a longer and more slender snout to feed off of the new prey

Thank you!

Compare and Contrast

• snout started short then progressively evolved to a longer one.
• evolved from land and water to marine then back to more shallow waters.
• the earliest ancestor was about 88 pounds where the modern crocodile is about 2,200 pounds having the weight grow steadily overtime.
• All three seem to have scales.

Intermediate Ancestor

• Name: Mesosuchia
• Habitat: Aquatic areas
• Fresh water and salt water
• Size: Not clear, probably in between modern crocodiles and Protosuchus
• Diet: Molluscs and large sea reptiles
• Physical Description:
• Paddle-like forelimbs due to the aquatic environment
• Very closely related to the modern Crocodile
• Longs snouts adapted for their diet
• Flat on the side of the skull
• Type: Reptile (marine)

Timeline of Crocodiles!

Protosuchus

Earliest Ancestor

Mesozoic Era

• Name: Protosuchus
• Habitat: Riverbeds of North America
• Size: 1 meter in length, 40 kilograms in weight
• Diet: Meat
• Physical description:
• It had a short jaw that broadened at the base of the skull.
• It had teeth in the lower jaw that fit into notches when closed.
• Strong tail for propulsion through water
• reinforced scales
• 2 rows of boney plates on its back
• Type: Reptile

55 mya- now

Crocodile

Jurassic- 210 million years ago

Mesosuchia

Modern crocodiles

• Habitat: Mostly freshwater habitats
• swamps
• rivers
• lakes
• Size: 5-23 feet long, and weigh up to 2,200 pounds
• Diet: Large game, fish and birds
• Physical description:
• Webbed feet for swimming
• 80 replaceable teeth
• Thick skin and scales
• smooth skin on their stomach and sides
• Green, brown or grayish in color usually