Armadillo in the context of "Pangolin"

Flea, the common name for the order Siphonaptera, includes 2,500 species of small flightless insects that live as external parasites of mammals and birds. Fleas live by ingesting the blood of their hosts. Adult fleas grow to about 3 millimetres (1⁄8 inch) long, are usually dark in color, and have bodies that are "flattened" sideways or narrow, enabling them to move through their hosts' fur or feathers. They lack wings; their hind legs are extremely well adapted for jumping. Their claws keep them from being dislodged, and their mouthparts are adapted for piercing skin and sucking blood. Some species can leap 50 times their body length, a feat second only to jumps made by another group of insects, the superfamily of froghoppers. Flea larvae are worm-like, with no limbs; they have chewing mouthparts and feed on organic debris left on their hosts' skin.

Genetic evidence indicates that fleas are a specialised lineage of parasitic scorpionflies (Mecoptera) sensu lato, most closely related to the family Nannochoristidae. The earliest known fleas lived in the Middle Jurassic; modern-looking forms appeared in the Cenozoic. Fleas probably originated on mammals first and expanded their reach to birds. Each species of flea specializes, more or less, on one species of host: many species of flea never breed on any other host; some are less selective. Some families of fleas are exclusive to a single host group; for example, the Malacopsyllidae are found only on armadillos, the Ischnopsyllidae only on bats, and the Chimaeropsyllidae only on elephant shrews.

Glyptodon (lit. 'grooved or carved tooth'; from Ancient Greek γλυπτός (gluptós) 'sculptured' and ὀδοντ-, ὀδούς (odont-, odoús) 'tooth') is a genus of glyptodont, an extinct group of large, herbivorous armadillos that lived from the Pliocene, around 3.2 million years ago, to the early Holocene, around 11,000 years ago, in South America. It is one of, if not the, best known genus of glyptodont. Glyptodon has a long and storied past, being the first named extinct cingulate and the type genus of the subfamily Glyptodontinae. Fossils of Glyptodon have been recorded as early as 1814 from Pleistocene aged deposits from Uruguay, though many were incorrectly referred to the ground sloth Megatherium by early paleontologists.

The type species, G. clavipes, was described in 1839 by notable British paleontologist Sir Richard Owen. Later in the 19th century, dozens of complete skeletons were unearthed from localities and described by paleontologists such as Florentino Ameghino and Hermann Burmeister. During this era, many species of Glyptodon were dubbed, some of them based on fragmentary or isolated remains. Fossils from North America were also assigned to Glyptodon, but all of them have since been placed in the closely related genus Glyptotherium. It was not until the later end of the 1900s and 21st century that full review of the genus came about, restricting Glyptodon to just five species under one genus.

Early European personifications of America, meaning the Americas, typically come from sets of the four continents: Europe, Asia, Africa, and America. These were all that were then known in Europe. The addition of America made these an even more attractive group to represent visually, as sets of four could be placed around all sorts of four-sided objects, or in pairs along the facade of a building with a central doorway.

A set of loose conventions quickly arose as to the iconography of the personifications. They were normally female, with Europe queenly and grandly dressed, and clearly the leader of the group. Asia is fully and richly dressed but in an exotic style, with Africa and America at most half-dressed, and given exotic props. One of the earliest and most persistent attributes for America was the parrot; these reached Europe by the early 16th century and were highly valued. The feather crown headdress, with the feathers standing up vertically, reflected the actual headgear of some American peoples. This personification was staged at Whitehall Palace in December 1613 by a dancer in The Somerset Masque wearing "a skin coat the colour of the juice of mulberries, on her head large round brims of many coloured feathers, and in the midst of it a small crown". A cornucopia, representing the new edible plants from the Americas, was a very common feature (although the familiar apple often seems the most prominent). America is often accompanied by an improbably placid caiman or alligator, reasonably comparable to Old World crocodiles, though the earliest images may show an exotic armadillo.

Keratin (/ˈkɛrətɪn/) is one of a family of structural fibrous proteins also known as scleroproteins. It is the key structural material making up scales, hair, nails, feathers, horns, claws, hooves, and the outer layer of skin in tetrapod vertebrates. Keratin also protects epithelial cells from damage or stress. Keratin is extremely insoluble in water and organic solvents. Keratin monomers assemble into bundles to form intermediate filaments, which are tough and form strong unmineralized epidermal appendages found in reptiles, birds, amphibians, and mammals. Excessive keratinization participate in fortification of certain tissues such as in horns of cattle and rhinos, and armadillos' osteoderm. The only other biological matter known to approximate the toughness of keratinized tissue is chitin.Keratin comes in two types: the primitive, softer forms found in all vertebrates and the harder, derived forms found only among sauropsids (reptiles and birds).

Incisors (from Latin incidere, "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, whereas armadillos, anteaters and other animals in the superorder Xenarthra have none.

A dermal bone or investing bone or membrane bone is a bony structure derived from intramembranous ossification forming components of the vertebrate skeleton, including much of the skull, jaws, gill covers, shoulder girdle, fin rays (lepidotrichia), and the shells of turtles and armadillos. In contrast to endochondral bone, dermal bone does not have a cartilage precursor, and it is often ornamented. Dermal bone is formed within the dermis and grows by accretion only – the outer portion of the bone is deposited by osteoblasts.

The function of some dermal bone is conserved throughout vertebrates, although there is variation in shape and in the number of bones in the skull roof and postcranial structures. In bony fish, dermal bone is found in the fin rays and scales. A special example of dermal bone is the clavicle. Some of the dermal bone functions regard biomechanical aspects such as protection against predators. The dermal bones are also argued to be involved in ecophysiological implications such as the heat transfers between the body and the surrounding environment when basking (seen in crocodilians) as well as in bone respiratory acidosis buffering during prolonged apnea (seen in both crocodilians and turtles). These ecophysiological functions rely on the set-up of a blood vessel network within and straight above the dermal bones.

A fossorial animal (from Latin fossor 'digger') is one that is adapted to digging and which lives primarily (but not solely) underground. Examples of fossorial vertebrates are moles, badgers, naked mole-rats, meerkats, armadillos, wombats, and mole salamanders. Among invertebrates, many molluscs (e.g., clams), insects (e.g., beetles, wasps, bees), and arachnids (e.g. spiders) are fossorial.

Xenarthra (/zɛˈnɑːrθrə/; from Ancient Greek ξένος (xénos), meaning "strange, foreign", and ἄρθρον (árthron), meaning "joint") is a superorder and major clade of placental mammals native to the Americas. There are 31 living species: the anteaters, tree sloths, and armadillos. Extinct xenarthrans include the glyptodonts, pampatheres and ground sloths, with some glyptodonts and ground sloths reaching sizes of several tonnes, much larger than any living xenarthran. Xenarthrans originated in South America during the late Paleocene about 60 million years ago. They evolved and diversified extensively in South America during the continent's long period of isolation in the early to mid Cenozoic Era. They spread to the Antilles by the early Miocene and, starting about 3 million years ago, spread to Central and North America as part of the Great American Interchange. Nearly all of the formerly abundant megafaunal xenarthrans became extinct at the end of the Pleistocene as part of the end-Pleistocene extinction event.