Amateur astronomers of the western hemisphere will be brandishing their homemade telescopes at the night sky next weekend, in likely fruitless attempts to catch a once in a century glimpse of the only known non human life outwith the earth’s atmosphere. The bounty of their ill equipped search however, is not your usual extra-terrestrial, but a species grown a little closer to home.

On Darwin’s tree of life, the nagarook lies close to the bough of the mammal branch, back when the thought of rearing your brethren in your own belly was a radical and risky venture. The gains were obvious. The gestated infant had ongoing access to a whole biosystem of nourishment, compared to the finite resources of a single egg, and thus could reach a more sophisticated stage of development before exposure to the dangers of the outside world.

The biology was complicated though. Space had to be found in already congested cavities, dynamic plumbing had to be installed to deliver the resources and take care of the sewage, and at the end of all this, the safe construction of an orifice large enough to extract the no longer tiny babies.

The nagarook can be looked upon as somewhat of a misstep on the path to fulfillment of this series of challenges. It maximised it’s internal volume by evolving into its spherical form that swelled at the pace set by the developing fetus. All organs barring the heart and lungs were spring cleaned out from the female’s bodies, outsourced to the males and accessed via genital plugs during necessarily frequent sexual contact. The entire abdominal cavity was lined with dense placenta.

So far so good. In fact, the nagarooks were so successful in conquering these first two challenges, that offspring were able to grow into a state of adolescence in the plush safety of the maternal womb.

This rendered the third challenge somewhat more difficult. Fossil records indicate the female nagarook genitilia were in fact elastic enough to deliver it’s teenage babies. Maybe the prospect seemed too painful. Maybe the pain was more emotional, saying goodbye to an internal presence of over 10 years. Or maybe it just wasn’t necessary.

Whatever the reason, somewhere along the line, nagarooks ceased to venture into the outside world whatsoever. Mates were chosen at the whim of one’s ancestors, and meta reproduction permitted through the unison of one’s ancestors’ genitals with one’s partner’s ancestors’ genitals. The largest specimen unearthed was 20 metres in diameter and contained 43 rings of the family tree, each generation nested within the last.

Inevitably, the nagarooks either died of natural causes, or acquired such a mass as to develop their own gravitational pull. When the moon was full, it would slingshot them off, one by one on their own orbits round the sun, only to be spotted once every thousand years. Conspiracy theories abound, but while it is highly unlikely they have survived the vacuum and velocity of their intergalactic travels, if you have an empty roll of toilet paper and a broken pair of spectacles, this weekend, perhaps you can see for yourself.