Teuthitheria

Introduction
Perhaps the most successful lineage of mammals alive are the unusual creatures known as the teuthitherians. Hundreds of species are known from across the planet, ranging from tiny hopping insectivores barely 6 centimeters long to armoured, hulking beasts weighing several tonnes. Although found on all continents, their true diversity can only be seen on the island continent of New Laramidia; where they unarguably rule supreme. The teuthitherians are a success story like nothing else; in a world dominated by amphibians and reptiles, they have risen from obscurity and taken the planet by storm, laying claim to the land, sea, and sky. Countless millennia of evolution have perfected them into one of the mammals’ greatest success stories; over half a billion years of adaption and survival from their first mammal ancestors have changed them into creatures unrecognizable to their forefathers and bizarre beyond imagination. Even though the Age of Mammals has come and gone many eons ago, the teuthitherians still show the Earth of a world that once was: when mammals ruled the planet. Although by this point, they could be barely be considered mammals anymore, having refined some rather generalist features of a long gone ancestral creature to extremes never before seen in the history of life on this world.

History


The earliest known ancestor of the teuthitherians was a species from near the end of the Quaternary Period, during the Cenozoic Era approximately 350 million years ago (MYA). Named Sus scrofa, it was a moderately large-sized, quadruped mammal that reached its peak at the end of the Holocene Epoch. It had a widespread distribution, with species known from practically all the continents at the time; it would not be unusual if they were present on all of them. Being the generalist, adaptable, and fast breeding (a few fossils have been found of pregnant females carrying somewhere between 5 and 10 infants) animals they most likely were, it is no surprise to anyone that they were so successful early on; examination of the skull show evidence that the distinct facial tentacles of the teuthitherians had already begun to develop, but at this time it was still a singular unit. However, despite their success, they were neither the most impressive nor the most diverse creatures on the planet; it was only after a catastrophic extinction at the end of the Quaternary Period (the cause of the extinction remains yet unknown) and after the extinction of most other mammals did they begin to diversify.

They (along with several other surviving species) brought in the Novogene Period approximately 340 MYA as the dominant animals on the Earth; their reign came to an end approximately 290 MYA as a massive series of volcanic eruptions in an area once known as the Mediterranean (now the northern region of the Afropian Desert) wiped out more than three-quarters of all species on Earth. The brought an end to the Cenozoic and doomed the mammals into small, insignificant niches once held by other groups. This also brought in the Stiliozoic Era: the Age of the Squamates. Sometime 130 MYA the first known true teuthitherians appeared, small, clambering creatures that hid in the presence of their massive scaly rulers, which had taken advantage of the warming of the Earth, dominating the world with an iron claw. The once mighty mammals (and some creatures known as “birds” that expanded into mammalian niches often) were forced into tiny scurrying animals, diversifying in secret, ready to take over the world once more whenever the opportunity came again.

Around 97 MYA, a massive comet almost 16km in diameter struck off the coast of what is now Aurora, creating one of the greatest mass extinctions in Earth’s history and bringing an end to Age of the Squamates; this ushered in the newest era in Earth’s history: the Ultrozoic. However it was not the mammals that rose to dominate the planet once more, nor was it the birds, in fact it was the small pond dwelling creatures once only common in the wetlands and rivers that rose from the ashes to reap the Earth and all that it offered; this was the dawn of the Age of the Frogs. The teuthitherians gave it a good shot near the beginning of this era, including producing some species that would eventually lead to the modern lineages; unfortunately as the anurans began to experience an explosion of diversity the already not as impressive collection of teuthitherians were no match for the amphibians and they slowly began to fade into extinction. Fortunately for them a continental ark appeared for them near the start of the Ultrozoic as the island continent of New Laramidia tore away from the supercontinent of Obcasis and brought a wide menagerie of teuthitherians with it, securing their place on Earth for a long time to come (a few species did tough it out on the mainland however, surviving to the present day). For over 85 million years they evolved in near-complete isolation from the rest of the planet; competition was fierce and thus as New Laramidia drifted close enough to Obcasis for faunal exchange between the two landmasses around 8 million years ago, they adapted very well.

Description


Although the bulk of their diversity if found on the continent of New Laramidia and some smaller offshore islands, they have a cosmopolitan distribution, common on every continent except Arabia where only a handful of species of pirg are found. Approximately 1 260 species are known, making them one of the most successful mammal clades still alive. They range from a few grams in weight to over 3 metric tonnes, and species have varied dietary styles and lifestyles that are very different from one another. It is very easy to tell what you’re looking at is a teuthitherian however; as there a number of distinct features that set them apart from both other living creatures and their ancestors.

The most noticeable and distinct feature of the teuthitherians is plainly obvious; a mass of long fleshy tentacles hangs from their faces. A structure unlike anything ever seen in land animals before (although some exceptionally well preserved soft fossils of extinct marine animals show of something very similar), between 4 and 8 long arms hang off the animals’ faces and have been developed into extremes in some forms (such as the pirgs, which have modified one pair into a set of wings). This structure is derived from the ancestral animal’s nose, which over time split in two, then four and six on the top jaw; later on, another pair developed from the lower lip. In most species, the tentacles are supported primarily of cartilage and muscle, but in some are stiffened by bone. As can be assumed, the tentacles of their upper jaw (being derived from a nose), end in nostrils, which are usually used for the mundane utility of breathing. One other very distinct feature of the teuthitherians are their teeth; two pairs of long tusks jut from their upper jaw (as well as another pair on the bottom jaw; the pair in the back of the top jaw are actually derived from a type of teeth otherwise known only in extinct mammals, called canine teeth). They are highly mobile, having a specialized set of jaw bones that are jointed, capable of moving the animal’s front teeth around; this is used very often to many species’ advantage, especially predatory species. In some species, the bones have re-fused, having become obsolete through lack of use. The front teeth are constantly growing, necessitating daily care; herbivorous species naturally wear them down through grazing and rooting around, carnivorous species tend to sharpen their teeth daily by scraping them against hard surfaces. Behind the front teeth are two pairs of simple pointed teeth derived from incisors and canine teeth, and three pairs of more ordinary molars.

The rest of the body plan of the teuthitherians usually varies wildly, but there are a few general features that are common in most or all members. The front legs of them have an extra joint, appearing extra long. The ancestral purpose of this joint is unknown but in most species it is simply another quirk with no particular usage. In some carnivorous species, it is used to extend their reach of prey and allows them to fold up their arms better. A few hopping species use this extra joint to literally put an extra spring in their step. The toe number of teuthitherians consists of a single toe in front and one or two in the back. Other general features include a general spareness of hair, an almost nonexistent tail, and a lack of external ears. A peculiar breeding method used by the teuthitherians is well documented; the infants are born with special pads on the bottom of their chest and tentacles on the lower jaw. Natural suction power and tiny hook-like structures derived from hair help the offspring grip their parents, riding along for the first few day or weeks of their life (some species do not practice this method however). The pads wither away after several weeks.

The sheer diversity of teuthitherians is unimaginably vast, especially considering the Era of Mammals has already passed by almost three hundred million years ago. But few can argue that they are not a success story that has beaten all odds and become one of the most wonderful and peculiar lineage of animals to ever exist on Earth.

Diversity
The true diversity of the teuthitherians is almost unimaginable; there are numerous species present on every continent and every sea, ranging from only a few grams to several tonnes in weight. They inhabit every niche imaginable, from grazers, to climbers, to browsers, to piscivores, to hunters, and seed-eaters; there are even parasitic and coprophagous species. In the 130 million years they have existed, they have conquered the toughest environments and beaten all the odds against a world in which the apex of mammals passed eons ago.