Eyelids are absent a sure sign of aquatic habits in a caudate. Giant salamanders are famous for, well, being giant, with record-holding specimens of the Chinese giant salamander reaching 1. Some fossil species were bigger, with A. Giant salamanders can inflict massive wounds with their teeth: during territorial fights males frequently sever digits, limbs, and bits of tails of rivals, and massive fatal slices across the neck — sometimes resulting in decapitation — are apparently not uncommon.
Chunerpeton from the Jurassic of China mentioned above has been identified as a cryptobranchid, in which case both this group and its sister-taxon Hynobiidae have been around for a long time. For much more on those species see the Tet Zoo article on giant salamanders link below. However, Estes later classified batrachosauroidids with proteids olms and mudpuppies and scapherpetids with ambystomatids.
They seem to have been large, long-bodied salamanders, probably with reduced limbs, with subtriangular, poorly ossified skulls superficially similar to those of amphiumas. They must have been large vertebral centra are usually something like 20 mm long , and the shapes of their vertebrae and limbs show that they were another long-bodied, limb-reduced, mostly aquatic group: in Scapherpeton from the Upper Cretaceous, the limb bones are small compared to the size of the vertebrae, the proportions seemingly being about intermediate between Dicamptodon and amphiumas Estes Sirens Sirenidae are perhaps the strangest of salamanders.
Superficially eel-like, neotenic, and lacking a pelvis and hindlimbs, they possess external gills, lack eyelids, are adept at burrowing in mud, and reach 95 cm in the largest species [Image above by Stan Shebs ].
The Cretaceous-Paleocene siren Habrosaurus reached 1. Habrosaurus , in fact, is so spectacular that I was half-expecting there to be some life restorations of it online there are two species: H.
The big surprise is that sirens have a horny beak and pavements of teeth on the palate. The beak forms a broad platform inside the jaws, and the jaw joint is ventrally displaced relative to the rest of the skull. All of these features are adaptations for crushing, and field studies show that as you might predict sirens feed extensively on gastropods and bivalves.
Sirens are unlike most salamanders in that their teeth are usually not pedicellate: that is, their teeth are not connected to the jaw bones by way of a flexible pedicle. Salamanders start their life as larvae without pedicellate teeth and normally develop the condition as they mature, so lack of pedicelly is seen as a neotenous condition.
Proteids also lack pedicellate teeth as adults, as do batrachosauroidids and the Jurassic salamanders Kokartus and Beiyanerpeton. Sirens also appear to be partially herbivorous, ingesting vascular plants and algae.
They have enlarged hindguts that may house symbiotic microbes Pryor et al. They are also unusual in that they can survive desiccation by forming a sort of mucus cocoon in the mud, a habit very similar to that better known for lungfishes.
Several features support the view that cryptobranchoids are anatomically primitive relative to the other crown-group salamanders, the salamandroids. Cryptobranchoids still possess an angular bone in the lower jaw, and they also practise external fertilization. In a radical departure from this view, Frost et al.
If Frost et al. The hypothesis that sirens are not members of Salamandroidea, then, appears more parsimonious on face value. Sirens have a fossil record extending back to the Upper Cretaceous, and while the extant species are all North American, fossil representatives have been described from Sudan, Germany, India and Bolivia. Given that salamanders are, as we've seen, mostly Northern Hemisphere animals, the presence of these animals in Gondwanan locations is significant.
The identification of these fossils — some of which have often been united in a group termed Noterpetontidae — as sirenids has been challenged Gardner This is the clade that contains the vast majority of salamander species and lineages, including the mostly American lungless salamanders or plethodontids, the chunky mole salamanders or ambystomatids of the Americas, and the mostly Eurasian salamandrids.
While its roots are in the Mesozoic, Salamandroidea is mostly a Cenozoic clade that exploded in diversity during the late Paleogene and Neogene. As all amphibian fans will know, they produce an elaborately shaped sperm package the spermatophore that they deposit on the substrate.
Some species are, err, well stocked and can produce multiple spermatophores in fairly rapid succession. Most remarkable in my opinion is the soft, dorsally projecting spike that some male salamandrids possess at the base of the tail. Once a female has expressed interest as a mating partner, the male manoeuvres himself to get beneath the female, and inserts the spike into her cloaca Sever et al.
What is it with evolution and its blatant disregard for rules and consistency? A moment ago, we looked at the bizarre sirens. Also long-bodied and super-weird are the amphiumas, or amphiumids. They have rather long skulls with unusually textured bone in the facial region and, unlike sirens, practise internal fertilization.
Amphiumas are reportedly of unpleasant temperament and are said to bite savagely. Surprisingly perhaps, amphiumas have been found to be the sister-group to the plethodontids Wiens et al. Incidentally, Edward Cope thought that amphiumas were ancestral to caecilians. Like amphiumas, proteids practise internal fertilization and are definitely parts of the IFS clade.
They have bushy external gills, laterally compressed tails and lack maxillae sirens also have reduced maxillae. Only two extant genera are recognised — Necturus from North America the mudpuppies and waterdogs and Proteus from Europe the olms. See comments]. Proteid monophyly has been found to be questionable in some studies Weisrock et al.
Proteids have been variously shuffled about the salamander family tree. The ish species of mole salamander, or ambystomatids, derive their name from their predominantly fossorial habits.
These are robust-bodied North American salamanders, some of which — like the Tiger salamander Ambystoma tigrinum — are large reaching 40 cm and brightly coloured. Particularly well known is the fact that some, like the Axolotl A. Two mole salamander species are particularly odd in that they consist only of females. Each side has 12 to 14 costal grooves. Plethodon cinereus. This lungless salamander is also known in a different phase as the leadback salamander.
It is long and slender. The redback is marked with a broad stripe that begins at the head and flows down the back and over the upper part of the tail, where the stripe shrinks in width. The stripe is usually red, although it sometimes may appear orange, yellow, pink or light gray. The sides are black, and this color extends upward to form a straight-edged border on each side of the stripe. The leadback color phase ranges from a light gray to almost black.
The solid color is shaded uniformly and does not have the colorful stripe along the back. A third color phase is found only occasionally. Marked with an unusual redness, it is referred to as an erythristic phase. The entire body, except for the belly, is red. Regardless of the color phase the belly is always mottled in a distinctive pattern of black and white. Each side has 18 to 20 costal grooves. Plethodon glutinosus glutinosus.
The slimy salamander is black, with a shiny coat that is marked with whitish or silver-colored spots. The spots are larger on the sides, but smaller and scattered over the back and tail. The belly is slate-colored and unmarked. The chin and throat areas are dark gray. Each side has 16 costal grooves. Plethodon wehrlei. Irregular spots, often looking more like dash marks, appear on the sides. They are white or bluish white in most cases, but sometimes can appear yellow.
The back occasionally is marked with very small flecks of a lighter color. The belly and the underside of the tail are evenly tinted in gray.
The throat is white or at least blotched with white. There are about 17 costal grooves on each side. Pseudotriton ruber ruber. Red is the primary body color. Even so, variations occur and it can be reddish brown to orange-brown.
The adults tend to be darker than the young. The sides shade toward a lighter tone as they approach an even lighter belly. The back and the upper portion of the sides are dotted with many and irregularly shaped jet-black spots. Small dark spots may appear on the belly. Sixteen to 17 costal grooves mark each side. You may be trying to access this site from a secured browser on the server. Please enable scripts and reload this page.
An Official Pennsylvania Government Website. Fishing Licenses. That is because, as adults, salamanders spend most of their time in forested areas, living under rocks and fallen logs or in underground burrows.
The best time of year to see these creatures is in spring when they move to wet areas to lay their eggs. These wet areas include ponds, ditches, marshes, meadows and a special, but little known habitat, called a vernal pool. There are many types of vernal pools, but generally a vernal pool is a low spot in a forest or meadow that fills with water during winter and spring and then dries out by late summer. It can be big or small. Because these pools are temporary, fish cannot survive in the pools, thus the eggs and hatching larvae of salamanders are safe from fish predation.
Habitats are usually destroyed during development or are degraded by pollution i. Many salamander species are localized and restricted to specific habitat types. Unfortunately, when these habitats are destroyed, the salamanders found there disappear too. Other than a few exceptions, salamanders do not relocate long distances to new habitats.
Even if suitable habitat is located nearby, migration is very difficult due to the numerous roads that dissect across Connecticut. When these slow-moving creatures cross roads particularly during spring migration to breeding pools , hundreds are killed by cars.
Make an effort to learn more about salamanders and take actions to conserve these special creatures. Following are some suggestions:. Most salamander species occur in temperate areas of the northern hemisphere. The United States is a salamander hotspot, with more species than any other country. Worldwide, nearly half of salamander species are threatened with extinction. Salamanders are central to food webs, connected to many other animal groups. What is PARC?
Partners in Amphibian and Reptile Conservation PARC is an inclusive partnership dedicated to the conservation of the herpetofauna--reptiles and amphibians--and their habitats. During the day they lounge under rocks or in trees to stay cool. At night they come out to eat. Their bright, colorful skin warns predators to stay away, according to the San Diego Zoo. Many salamanders have glands on their necks or tails that secrete a bad-tasting or even poisonous liquid.
Some can also protect themselves from predators by squeezing their muscles to make the needle-sharp tips of their ribs poke through their skin and into the enemy. Some species can shed their tails during an attack and grow a new one. The axolotl, an aquatic salamander, can grow back limbs lost in fights with predators and damaged organs due to a special immune system. Salamanders are carnivores, which means they eat meat instead of vegetation.
They prefer other slow-moving prey, such as worms, slugs and snails. Some larger types eat fish, small crustaceans and insects. Some salamanders eat frogs, mice and even other salamanders. Many salamanders lay eggs, but not all.
The alpine salamander and fire salamander give birth to live offspring, for example.
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