Susan has an unusual pet, a chameleon. She is a herper. Every month Susan and her fellow herper friends meet in one of their garages and exchange snippets of information on the animal kingdom.
Well, let’s not wait and indulge in the whirlpool of knowledge!
There are 11,136 reptile species and 8,000 species of amphibians inhabiting Mother Earth.
In one of Susan group’s monthly meetings, each one had to come with 1-liner jokes on reptiles and amphibians. Susan was the first to go. She began,
Hey guys !!
- Q: What do you say when you meet a toad?
- A: Wart’s new ?!!
Greg followed with,
- Q: What is a reptile’s favorite recreational drug?
- A: Mari-iguana
Soon, they got busy with putting together notes for an introductory seminar on reptiles and amphibians for kids at a school. They made sure that the records were simple for them to read out to the kids.
Important Differences Between Reptiles and Amphibians
Primarily, ‘reptile’ is the name given to creeping and crawling animals and ‘amphibian’ to animals who live dual lives. In a sense, they spend the first half of their life in water and the other half on land. Some of the essential differences between reptiles and amphibians emanate from their physical appearances and life cycle. Some of these differences are:
- Habitat: Reptiles usually inhabit the land except for turtles and crocodiles.
- Larval Stage: Reptiles spend larval and adult stage on land Unlike amphibians, reptiles do not undergo the aquatic larval stage
- Metamorphosis: Reptiles do not undergo metamorphosis
- Skin Type: They have dry, hard and scaly skin
- Feeding: Reptiles swallow their prey whole
- Respiration: They breathe with their lungs, though there are exceptions, such as the aquatic turtles. These turtles exhibit the limited ability to exchange gas underwater during elongated periods of cold temperature or inactivity.
- Physiology: The heart of reptiles is three-chambered with a septum dividing the ventricle further.
- Neck Vertebra: They have multiple vertebrae in the neck. This allows head articulation.
- Mode of Reproduction: Reptiles are mostly oviparous; while some are viviparous as well.
- Fertilization: The eggs of reptiles fertilize internally.
- Limbs in reptiles facilitate running and swimming
- There is a hard leathery or calcareous shell-like protective covering to the eggs of reptiles
- A reptile plays dead or retreats into its shell to evade danger.
- When faced with danger, reptiles release foul smell to alert potential predators. Reptiles such as snakes hiss or shake their tail tip, while the horned lizard squirts foul-tasting blood from its eyes.
- They secrete toxins from their teeth and nails to ward off predators.
- Some reptiles have an additional sense organ located on the roof of the mouth. The organ captures chemical molecules and thus helps locate mates, prey, and predators. Thermoreceptors on the face of snakes enable them to find prey in the dark.
- Reptiles can visualize and distinguish different colors owing to the wide range of the color spectrum.
- Habitat: Amphibians live on land as well as in water
- Larval Stage: Amphibians spend larval stage in water and adulthood on land. Most amphibians use gills while their lungs develop.
- Metamorphosis: Most amphibians undergo a biological process called metamorphosis, a complete physical change in the form and structure of an animal after hatching till attaining adulthood.
- Skin Type: They have smooth and extremely porous skin
- Feeding: Some amphibians have exclusive teeth to chew their prey while most swallow their prey too
- Respiration: Amphibians breathe via gills, lungs, or through the skin (cutaneous). An exception is the Lungless Salamander, which respires through its skin and tissues in its mouth.
- Physiology: They have a three-chambered heart.
- Neck Vertebra: A single vertebra in the neck restricts head articulation in this species.
- Mode of Reproduction: Amphibians are oviparous.
- Fertilization: The eggs of amphibians fertilize externally.
- They have webbed feet to swim and run.
- A coating of gel is present on the eggs of amphibians.
- They can keep off predators due to their nocturnal activity and aposematic coloration, i.e., change in the color of an animal’s body to display a warning to the predator.
- Amphibians can escape predators owing to their slippery skin. In case it is caught, it secretes an extremely unpleasant toxic substance from its skin. This forces the predator to reject the prey.
- They secrete toxins from their skin to protect themselves from predators
- Some amphibians (tadpole) use their lateral line, a unique system of tactile sense organs, to sense changes in water pressure to locate prey.
- Q: What’s the coldest type of reptile?
- A: A Blizzard
How and why differences arose between reptiles and amphibians?
Interestingly, many millions of years ago, there was no classification between reptiles and amphibians. Both these animal species shared several similarities. Later on, scientists attributed these similarities to the fact that reptiles were but an evolutionary avatar of amphibians.
The origination of reptiles dates back to 320-310 million years ago in the swamps of the late Carboniferous period. The first reptiles are known to have evolved from advanced reptiliomorph labyrinthodonts. Hylonomous is the oldest, undisputed reptile known. Its footprints, showing reptilian toes and imprints of scales dating back to 315 million years ago, were discovered in Nova Scotia. Westiothiana and Paleothyris are some other members of this species. Mesosaurus is one of the best known early reptiles.
Increasing evolutionary pressure and evolutionary changes stoked by the vast expanse of land led the amphibians to adapt more and more to land. Environmental selection led to the development of certain physiological features. In all of the morphosis, the development of lungs and legs is main. While the development of external eggs became the identifying factor of the class, Reptilia. Also, yet another significant growth was in the sizes of cerebrum and cerebellum. These enlarged organs play a crucial role in guiding the reptiles at the time of hunting.
The rise of reptiles began after larger stem-tetrapods began to better adapt to drier conditions following the collapse and elimination of primitive tetrapods during the Carboniferous Rainforest Collapse. Also, they adapted faster to newer ecological conditions and were able to lay their eggs on land.
They acquired new niches at a rate faster than the primitive tetrapods and that before the collapse. They became omnivores, from being only insectivores and piscivores. From here on begins the domination of reptiles and the proliferation of its varied species. Thus, began the commencement of the Mesozoic Age or the Age of Reptiles.