History UsefulNotes / PrehistoricLifeNonDinosaurianReptiles

* Snakes or Ophidians are the great exception among extant reptiles: they are a ''very'' recent thing, appearing only in the Late Cretaceous, just before the mass extinction. But their success was obtained only since the beginning of the Mammal Age 65 million years ago, and venomous species like the elapids (cobras, sea-snakes, and relatives) and the viperids (vipers, rattlesnakes, and relatives) appeared even later, 30-20 million years ago. The most ancient extant snakes are probably boas and pythons, or at least their closest relatives: the most common kind of snakes today, the colubrid snakes (grass snakes, rat snakes, and relatives), appeared in fully Cenozoic settings. The least-known among modern snakes, the small wormlike [[http://en.wikipedia.org/wiki/Scolecophidia blind snakes]] (typhlopids and relatives), are considered primitive like or more than the pythonids and the boids. Their resemblance with the equally poorly-known Amphisbaenians (earthworm-looking, usually limbless lizards) is coincidental, as the two groups of squamates are not closely related. Snakes today are very abundant: with more than 3,000 species they are the second biggest group of reptiles after birds. Among traditionally-intended "reptiles" only the non-snake/non-mosasaur squamates, aka the commonly-intended "lizards", have even more species (maybe 5,000). The turtles have today 300-400 species, the crocodilians less than 30 species, the tuataras only one. On the other hand, birds (which are also reptiles, being most closely related to crocodilians) reach today a whopping ''10,000 species''. (twice as much as all modern mammal species combined, and roughly equivalent to the number of non-avian reptile species combined).

* Snakes or Ophidians are the great exception among extant reptiles: they are a ''very'' recent thing, appearing only in the Late Cretaceous, just before the mass extinction. But their success was obtained only since the beginning of the Mammal Age 65 million years ago, and venomous species like the elapids (cobras, sea-snakes, and relatives) and the viperids (vipers, rattlesnakes, and relatives) appeared even later, 30-20 million years ago. The most ancient extant snakes are probably boas and pythons, or at least their closest relatives: the most common kind of snakes today, the colubrid snakes (grass snakes, rat snakes, and relatives), appeared in fully Cenozoic settings. The least-known among modern snakes, the small wormlike [[http://en.wikipedia.org/wiki/Scolecophidia blind snakes]] (typhlopids and relatives), are considered primitive like or more than the pythonids and the boids. Their resemblance with the equally poorly-known Amphisbaenians (earthworm-looking, usually limbless lizards) is coincidental, as the two groups of squamates are not closely related. Snakes today are very abundant: with more than 3,000 species they are the second biggest group of reptiles after birds. Among traditionally-intended "reptiles" only the non-snake/non-mosasaur squamates, aka the commonly-intended "lizards", have even more species (maybe 5,000). The turtles have today 300-400 species, the crocodilians less than 30 species, the tuataras only one. On the other hand, birds reach today 10,000 species (twice all the modern mammals).

* Phytosaurs have a very weird name: "[[CarnivoreConfusion plant lizards]]". A much more apt name for this group is Parasuchians, "near crocodiles". Phytosaurs indeed were the most crocodile-like among all Triassic reptiles, and occupied the freshwater predator niche outcompeting temnospondyl amphibians. But then, ''true'' crocodylomorphs took their place in turn, after the Triassic-Jurassic extinction event wiped the phytosaurs out.[[note]] The Chinese ''Pachysuchus'' was once considered an Early Jurassic parasuchian, but is most likely a sauropodomorph dinosaur.[[/note]] Phytosaurs could reach large size (5 m the most), but had very short limbs and long, thin jaws often similar to a modern gharial. However, it's easy separate them from crocs, by one feature: their nostrils were ''just in front of their eyes'', a bit like whales. Though once thought to be croc-line archosaurs (pseudosuchians), new analyses have shown that phytosaurs are likely outside of crown Archosauria altogether. ''[[UsefulNotes/StockDinosaursNonDinosaurs Rutiodon]]'' is one of the most portrayed, because it lived alongside ''Coelophysis'' and was a [[NeverSmileAtACrocodile potential predator]] of the latter.

* Turtles have ''literally'' been among the longest-lived reptiles ever, since appeared 230 million years ago and are still living today. But their origin has long been really mysterious. The very first turtles ever discovered, among them ''[[http://en.wikipedia.org/wiki/Proganochelys Proganochelys]]'' (also called ''Triassochelys'') from [[ExactlyWhatItSaysOnTheTin the Triassic]], had already the classic turtle shape, shell and toothless beak included; since then, they have not changed their body plan at all for 250 million years. Mesozoic turtles were ''very'' similar to ours. They have had a great success, colonizing all three main habitats just like crocs, terrestrial, marine, freshwater (but unlike crocs they frequent all these environments still today); however, like crocs, freshwater has been the favourite one, while terrestrial and seagoing species have always been a minority.

* Many modern lizards are still compared with dinosaurs, or even passed off as "mini-dinosaurs", in documentaries and pop books; ironically, just because they were used in the past as a model for the early dinosaur paintings and models. This spread the popular notion that ''all'' prehistoric reptiles were nothing but "giant lizards": a notion then adopted by films, comics and whatnot, which has given to us the {{Slurpasaur}} trope. But lizards actually pertain to a ''very different'' group of reptiles than dinosaurs and even crocodiles (both archosaurs); this group is called the [[http://en.wikipedia.org/wiki/Squamata squamates]] (literally "the scaly ones"). Together with the sphenodonts (see below), squamates form in turn the Lepidosaurs. One may even hear the largest modern lizards ''literally'' passed off as dinosaurs in documentaries or other non-fictional works; the predestined victim is, obviously, the large monitor lizard called [[http://en.wikipedia.org/wiki/Komodo_dragon Komodo dragon]]. The astonishing thing is, our Indonesian "dragon" did have in the recent past a close Australian relative much, much larger than itself: ''[[UsefulNotes/StockDinosaursNonDinosaurs Megalania prisca]]'' (also known as ''Varanus priscus'') was 20 ft long, ''twice as long as its Komodo kin''; like its contemporary (this was a modern animal that lived with and was wipe out by humans) it was highly intelligent, as smart as most carnivorous mammals, was a fast runner, had shark-like teeth, produced venom, and lived ''just 50,000 years ago''. It was, arguably, one of the most powerful predators of its habitat. But don't forget the contemporary mekosuchine land croc ''Quinkana'', which was as big and as fast as the megalania, with equally strong teeth and the typical armored body of a crocodile (but lacking the venomous saliva), and ''Thylacoleo'', the [[UsefulNotes/StockDinosaursNonDinosaurs marsupial lion]]: though not larger than a lion, some scientists think this relative of kangaroos and koalas was the most efficient mammalian predator ever, maybe even capable to kill a fully-grown ''Megalania'' or ''Quinkana'' if it was lucky! ''Megalania'' is by far the largest lizard that ever lived. But wait... have we forgotten something? Yeah, the mosasaurs. It's so easy to forget this, but they ''were'' true lizards, and were distant relatives of the monitor lizards. They ranged in size from small 1 m/3.3 ft proto-mosasaurs like ''[[http://en.wikipedia.org/wiki/Opetiosaurus Opetiosaurus]]'' to giants like [[UsefulNotes/StockDinosaursNonDinosaurs ''Mosasaurus'' and ''Tylosaurus'']] that grew to more than 16 m/50 ft in total length and up to 10 tons of weight (approximately as heavy as a large male orca), the ultimate size-record belongs definitively to them. Along with ''Megalania'' and the Komodo dragon, mosasaurs are the only "giant lizards" which are TruthInTelevision. But wait… we've still forgotten something: yeah, anacondas and reticulated pythons, which can be 10 m/30 ft long and weigh up to 150/200 kgs. See below.