Tam

Tams, sometimes also called tamows or tamshrews, are a subgroup of shrews characterized by the presence of protective armor and tail ornamentation, in contrast to the hedgehog- or porcupine-like quills of their more primitive ancestors and relatives. They are the crown group of furred shrews; any living furred shrew without armor or tail ornamentation has lost those features secondarily.

Tams originated on the now-sunken Jaydoh Island, but thanks to seafaring representatives they have since spread to all landmasses.

Anatomy
Tams are generally furry quadrupeds. They usually have two or three types of integument; they have fur which they inherited from their ancestors, and they may have either keratinous scales or osteoderms for armor. Even "unarmored" species often retain scales on their tails, though there are exceptions. Most species have whiskers on their lips, which are mainly used for sensory purposes.

Most tams have marsupial-like reproduction, though a few branches have increased their gestation time. Tamjacks are placental, but they ancestrally retain the pouch. Ancestrally, the external reproductive anatomy of the males resembles that of a boreoeutherian mammal (in that they have a penis, and external testes placed between it and the anus), but the tamjack subgroup internalized their testes.

Like most Spondylozoans, tams have six eyes and red iron-based blood.

Behavior
As such a diverse group, tams vary greatly in their general behavior. They all perform parental care, but whether this is the effort of a single mother, a mated pair, or a communal group varies from species to species.

Species which construct complicated nests are able to coordinate well enough to work together on them without conflict.

Intelligence
Though only one tam, the Seashrog, is generally famed for its intelligence, it isn't smart in isolation. The nest-building techniques present in tams can be very complex, indicating the high intelligence required to construct them is ancestral and already present in most groups. For instance, the nests of the Pickaxe Tamow, which is nearly on the opposite side of the tam family tree from the seashrog, are incredibly advanced, making use of wells and chimneys to access water and control air circulation.

Evolution
Tams first appeared in the Masonian period, the first species being the Scaleback Tamow. Native to Jaydoh Island, this early species had derived the hedgehog-like quills of its more primitive ancestors into keratinous armor plates. A medium-sized herbivore, its main predators of the time were Jaydoh's native clade of large carnivorous saucebacks, which were descendants of the Jaydoh Waxface.

In an unprecedented turn of events, in the early Darthian period, a semi-aquatic tam--the Marine Tamow--appeared. As if in anticipation of the island sinking, this superficially beaver-like tam constructed floating nests, which allowed it to leave the island and colonize new habitats. This led to it giving rise to three notable kinds of tam, including Dixon-native Pickaxe Tamow, Barlowe-native Tamchuck, and the Tamjack which remained at sea.

Barlowe-native descendants of the Tamchuck would be affected heavily by habitat loss, radiating briefly only to be trimmed down to just a few species as Barlowe sank into the ocean. However, this did not stop this branch from producing armorless arboreal forms and even large carnivores, which still have some surviving representatives.

Descendants of the Tamjack, which remained out at sea to improve their nest construction, were not so lucky, radiating into many forms on various islands only for all of them but the original Tamjack to die of habitat loss by the start of the Bonoian period. Still, the sole survivor was able to produce a second radiation, which has gone global and may be far more successful going forward. The largest furred shrews to ever live are of the Tamjack clade. Their own evolution being fairly unique and complicated, this subgroup of tams actually has their own page.

Perhaps the most successful are the Dixon- and later Darwin-native descendants of the Pickaxe Tamow. Like their Barlowe counterparts, they produced armorless and large carnivorous forms, though the former staying on the ground as burrowing opportunists and the latter being cursorial and dog-like rather than bulky and cat-like. This clade produced the smallest furred shrew to ever live.

Size and Diversity
Tams include both the largest and smallest furred shrews to ever evolve, ranging from diminutive mouse-sized creatures to enormous armored megafauna rivaling the largest land mammals on Earth.

While their diversity hardly seems impressive when compared to Terran mammals, it's important to note that prior to tams, furred shrews had never been particularly diverse at all, with only a small handful of species being extant at any given time and there often being very little variation between them. The diversity of tams is only rivaled by the very first radiation of furred shrews, which were ground down to only a single species by the Shrew Plague.