Reptiles- Class Eusuchia- Crocodilians, Order Squamata, Class Chelonia

Overview of Crocodilians, Lizards, Snakes, and Turtles

The Reptiles

scales (water retention), shelled eggs with amniotic membrane, internal fertilization (hemipenis- forked penis), poikilotherms (Fancy for ectotherms), more rigid skeleton, legs pulled under body, 3 to 3.5 chambered heart (some walled “septum” that separates the ventricle)

Reproductive Types

Oviparous- egg layers, Viviparous- live birth, placental, Ovoviviparous- “hatches” in adult, then birthed

Class Reptilia (traditionally)

Order Crocodilia- alligators, crocodiles, caimans, Order Squamata- lizards and snakes (suborder Lacertilia-lizards, suborder Serpentes-snakes), Order Testudines- turtles

Class Reptilia (now accepted)

Class Chelonia- Turtles, Class Reptilia (Order Squamata- lizards and snake; Suborder Lacertilia-lizard, Suborder Serpentes-snakes) Class Eusuchia- Crocodilians

Class Eusuchia

Crocodilians

Big, toothed, semi-aquatic, lizard shaped, 1 species in Alabama-American Alligator (South Florida has the American Crocodile), Big Carnivore, Growth 1 foot per year, but after 6 ft they gain girth (50-75 years age), Range below Fall line, but small areas North, lays eggs; mud/grass nest, PATERNAL CARE, has ridge-fins on back that use for hydrodynamics

Class Reptilia, Order Squamata: Suborder Lacertilia-Lizards

19 families worldwide (Greater than 3800 species), ALL continents except Antarctica, More common in warm area, SW of NA is the center of evolution, thermoregulation by basking, limbs are well-developed, occupies almost all niches/habitats, most lay eggs; some give “birth” (ovoviviparous), 2 venomous lizards in the world

12 native species of lizards in Alabama (Lacertilia-Lizards)

1 invasive gecko, all carnivorous, all lay eggs, 3 legless forms in AL, Snakes vs Lizards (eyelid- snakes NO, lizards YES; external ear openings- snakes NO, lizards YES)

Class Reptilia, Order Squamata: Suborder Serpentes-Snakes

Striking range is half their body length, elongate; scaly body with no legs, eyelids, OR ear openings, 2700+ species (25% are venomous), 40 species in AL (6 venomous)

Venom is a complex mixture or enzymes of various sizes and activities (Suborder Serpentes-Snakes)

Changes based on age, based on target desired; or a soup of enzymes of both: neurotoxins- stops/slows the transition of neural activities (QUICKER ACTING, more in smaller snakes), hemotoxins-break down red blood cells bursts capillaries (more related to vipers)

You are just bit by a venomous snake…

Hospital as soon as you can, stay calm (blood circulates with heart rate), with anti-venom, light tunicate

Reproduction- hemipenis (forked penis) (Suborder Serpentes-Snakes)

Mating after brumation (similar to hibernation) or in fall depending on species (rattlesnakes and cottonmouths)

70% snakes world-wide lay eggs, 30% snakes are ovoviviparous (Suborder Serpentes-Snakes)

In AL, Pit Vipers, Water Snakes, and Garter Snakes