Alcyoneucaputia

**Alcyoneucaputians** are a clade of celernantids that are alive today.

## Evolution and taxonomy

Alcyoneucaputians are the basalmost spinocaputians. Spinocaputians are a clade of largely "jawed" crucissymbioticans, but unlike many other jawed dispeculates, they do not largely rely on hyoid bones to form their jaws, but instead on hardened ramifications of their proboscis, often with the support of cartilaginous joints to aid in their motion. Although, paleontological and anatomical analysis seem to suggest these "jaws" have evolved independently in some groups of spinocaputians as a result. The basal spinocaputian is expected to have had semi-fused three proboscis, each with its own armour plating at the tip, and eventually ramified into long strings branching from the armoured tip in some species. Alcyoneucaputians themselves evolved 90 million years ago in the Compsogene, but they share a common ancestor with the related and more diverse spinodontians, some 181 million years ago in the Scelusian. Spinodontians themselves evolved shortly after 171 million years ago in the Scelusian as well.

Spinocaputia (181-0)

* Alcyoneucaputia (90-0)
	+ Alcyoneum comedenti
	+ Ros caput
* Spinodontia (171-0)

## Characteristics

Alcyoneucaputians are relics of a long lost past, but structurally they are not very different from what would be expected for the evolution of a basal spinocaputian. Their lateral proboscis are fused with hardened exterior plates, with the orifices of the respective proboscis being held at the base of the lower jaw. The central proboscis does a simillar job as an upper jaw, fused with the rostrum by an hardened external plate, and the orifice of this one is also positioned at the base of the upper jaw. Thanks to cartilaginous rods, they are able to move the heavy lower jaw like a tetrapod one. A pretty original form of forming a jaw. As a result their proboscis do not come out of the mouth to feed, and they therefore have to chew their food. At the borders of the mouth, "teeth" exist to help strip off the food. Their entire skeleton is cartilaginous. They have lost their bony limbs, unlike spinodontians. The eyes of the alcyoneucaputians are pretty advanced, with a focalized lens to help them see their surroundings, no longer having the typical basal compound eye. This was likely an adaptation to see the surroundings better and escape predators as they swim fast enough. Advanced eyesight is pretty odd for many herbivores, so the true nature of their evolution is yet to be understood. They move thanks to their vertical tail fluke. They have external armor at the front of their head. Their respiratory orifices are organized by several and very thin slit-like gills, that allow efficient oxygenation as they swim. Despite all of these advanced adaptations, alcyoneucaputians are a very reduced group isolated in one corner of the globe.

Alcyoneucaputians are very small creatures. The largest is Alcyoneum comedenti, with 30 cm in length, while Ros caput is the smallest, being 10 cm long.

## Distribution and habitat

Alcyoneucaputians are a clade highly restricted to only one region of the globe, the safe haven for old groups of marine taxa, the reefs of Isla Inferno. They are all found in the shallow reefs of the island, exclusively marine creatures.

## Diet

Alcyoneucaputians are exclusively herbivorous. They use their jaws and small teeth, to strip off the floral material they feast on the reefs.

## Behaviour and sociality

Alcyoneucaputians are largely solitary, though some have been observed living in small groups.

## Reproduction

Alcyoneucaputians are oviparous. To impress mates, they clap their jaws to create underwater sounds, sort of like the chirps of crickets. They do not take care of their eggs, so they will lay a few of them in shallow waters. They practice external fertilization. The male fertilizes the eggs laid by the female. Once they do, the parents abandon the eggs to their fate.