Accordingly, many species also lack an aquatic larval stage, a phenomenon known as direct development in which the offspring hatch as fully-formed, miniature adults.

The lift of this constraint allowed widespread colonization and diversification within a broad number of terrestrial habitats which is a testament to the high success and proliferation of Plethodontidae.

[5] Many species have a projectile tongue and hyoid apparatus, which they can fire almost a body length at high speed to capture prey.

[6] An estimated 1.88 billion individuals of the southern redback salamander inhabit just one district of Mark Twain National Forest alone, about 1,400 tons of biomass.

[7] Due to their modest size and low metabolism, they are able to feed on prey such as springtails, which are usually too small for other terrestrial vertebrates.

Plethodontids exhibit highly stereotyped and complex mating behaviors and courtship rituals that are not present in any other salamander family.

The male will twist his body around and deposit a sperm capsule, known as the spermatophore, on the substrate in front of the female's snout.

During the breeding period, males will grow enlarged anterior teeth used to scratch the female's skin on her head as a part of the courtship ritual.

[15] Plethodontids can tolerate hypoxia for prolonged periods by reducing their metabolic rate instead of by relying on anaerobic cutaneous respiration, as initially theorized.

The groove is lined with glands, and enhances the salamander's chemoreception which is correlated with a higher degree of olfactory lobe and nasal mucous membrane development in plethodontids.

Though some lunged salamanders do exhibit similar structures, they are reduced in size and are not arranged near the nostrils (i.e. nares) in the same fashion as plethodontids.

[24] A single hemidactyliine (Palaeoplethodon) is known from Miocene fossil remains preserved in Dominican amber, marking the only record of salamanders in the Caribbean.