The size of reptiles' brains relative to their bodies is much smaller than in mammals. ¹⁾

In turtles, alligators, some lizards, and some fish, thermal sex determination occurs; that is, the sex of the young depends on the temperature at which the eggs develop. Higher temperatures induce females, while lower temperatures cause only males to hatch; intermediate temperatures cause individuals of both sexes to be born. These animals do not, like most vertebrates, have sex chromosomes; instead, genes responsible for sex are present in all individuals but are activated or not depending on temperature. ²⁾

Reptiles use various methods to defend themselves from dangerous situations, such as avoidance, camouflage, hissing and biting. ³⁾

A mysterious dinner snake (Cenaspis aenigma) was found in the belly of another snake killed by a fruit harvester in the Mexican state of Chiapas. Until the description of the holotype from a partially digested male specimen in 2018, no other specimens of this species had been found, either alive or in museum collections despite numerous expeditions organized to the site where the first specimen was found. Features have been detected, distinguishing it from all known representatives of snakes so far. ⁴⁾

Australia has more venomous snakes than non-venomous snakes. The Taipan is one of the most common venomous Australian snakes. ⁵⁾

The flag and coat of arms of Martinique each feature four snakes. The snake in the coat of arms - the lanceolate broom, caixa - is the only venomous snake found on Martinique and St. Lucia. On the islands (also Trinidad and Tobago), it was artificially acclimated by planters so that its presence in the bush and jungle would deter slaves from fleeing the plantations. Caixa venom contains reteplase, used in laboratory diagnostics to assess the timing of the batroxobin (plasma coagulation) clotting system. ⁶⁾

There are more than 8,000 species of reptiles on the planet, and on every continent except Antarctica (where it's just too cold). ⁷⁾

All Bothrops have one thing in common - they have cavities on each side of their heads under their eyes that look like large nasal openings. The thin membrane that lines the bottom of the cavities is dotted with receptors (numbering between 500-1500 per mm²) that can register small temperature differences. ⁸⁾

Nearly two-thirds of snakes are not venomous. Only about 500 species of snakes are venomous, of which only 30-40 are considered harmful to humans. In other words, less than 2% of all snakes are considered harmful to humans. ⁹⁾

Leatherback turtles are some of the deepest diving marine animals, with recorded encounters at depths of 3000 ft. Due to the pressure there, such depths are unattainable for turtles with hard shells that would be crushed. ¹⁰⁾

The first reptiles are believed to have evolved around 320 million years ago. ¹¹⁾

The scales of all snakes and many lizard species are made of keratin, which is the same substance that makes up human hair and nails. ¹²⁾

The last recorded death by adder bite in the UK was recorded in 1975. ¹³⁾

There are no reptiles and amphibians living in the wild in Iceland. ¹⁴⁾