Cenohadros

The information here is mostly **FICTIONAL**. Do not be fooled!

Male C. astronomicus spotted in Germany

Range of C. astronomicus. Red indicates current distribution and pink indicates maximum distribution during the Pleistocene

***Cenohadros*** (meaning "Cenozoic hadrosaur") is a genus of microcenohadrosaurian neolambeosaur cenohadrosaur from the Pleistocene and Holocene periods of Europe. It contains only one species, ***Cenohadros astronomicus***. It is the first cenohadrosaur and the first non-avian dinosaur described from the Cenozoic era.

## History of research

### Earliest find – Cancello's specimen

The holotype of *Cenohadros* is a nearly complete albeit slightly decayed carcass of an adult individual. It preserves most of the skeleton, musculature, and integument, although the skull and most of the tail are incomplete, possibly as a result of scavenging.

The specimen was first discovered by Italian farmer Adamo Cancello while looking for truffles in the mountains of Tuscany, Italy. Initially thought to be a deer, the carcass was reported to the Italian police, who then referred it to several of Italy's top biologists, who concluded that it represented a species unknown to science. It was quickly realized to be a hadrosaur, becoming a media sensation across the world. For the first time, the world had undeniable proof that non-avian dinosaurs survived to the modern day.

Of course, this news was not without its detractors. Several believed the specimen was an elaborate hoax created by Cancello to gain attention, but this was quickly refuted by the fact that the skeleton and DNA closely resemble what is expected for a hadrosaur, something that a farmer like Cancello would likely not be able to fabricate. The question then became how the hadrosaur ended up in modern-day Tuscany.

### A creature from another dimension

This is where the *Inter-Temporal and Inter-Universal Commission on Natural History* (IICNH) stepped in. They originally believed the specimen to be an "anomaly"–a vagrant from the Mesozoic that got stranded after the closure of an intermittent time portal. However, because the specimen's anatomy did not match any known Mesozoic hadrosaur, the IICNH decided to investigate. They went to the location where Cancello had found the carcass and were surprised to discover a permanent portal to a dimension where hadrosaurs survived into the Cenozoic alongside birds, which they called the "Cenohadrosaur timeline". The IICNH sent a fifty-man expedition–later known as the "Cenohadrosaur team"–to the portal.

After several years of research, the Cenohadrosaur team (including Cancello as an honorary first author) released the first scientific paper about the Cenohadrosaur timeline. It contains in its appendix the description of *Cenohadros astronomicus*, the first formal description of a Cenozoic non-avian dinosaur. The chosen generic name, "*Cenohadros*", is derived from the Greek words *kainos*, meaning "new", and *hadros*, meaning "sturdy", intended to be a contraction of "Cenozoic hadrosaur", referring to its classification and time period. The specific name, "*astronomicus*", is Latin for "astronomical", and is intended to represent the "astronomical" odds of finding a non-avian dinosaur in the Cenozoic. Cancello's specimen was designated as its holotype, and was given the identification number **NHMCT 0001**, "NHMCT" referring to the "Natural History Museum of the Cenohadrosaur Timeline", a collection of fossils and other specimens from the Cenohadrosaur timeline.

## Description

With at least fourteen specimens discovered, including carcasses, fossils, and live specimens, the entire anatomy of *Cenohadros* is known, offering valuable comparisons with earlier Mesozoic relatives. As is general for cenohadrosaurs, the overall silhouette of the body is similar to that of the extinct *Tethyshadros*, being a purely quadrupedal animal with a gracefully-muscled torso, long, stiffened tail, and gracile yet powerful limbs. The manus was monodactyl, with only the second finger present, encased in a fleshy pad tipped with a large, horse-like hoof. Like other microcenohadrosaurs, it had digitigrade hindlimbs that lack the fleshy pad connecting the ankle to the ground, creating a convergently theropod-like form.

The skull of *Cenohadros*, however, is a far cry from its Mesozoic relatives. With its round shape and enlarged beak, it externally looks more similar to extinct basal ceratopsians like leptoceratopsids, but with crests formed from expanded nasal bones like other hadrosaurs.

At the time of its description, the shape of *Cenohadros'* crest was unknown, as Cancello's specimen did not have the crest preserved. It was originally thought to be a solid, bulging nasal boss, consistent with its initial interpretation as a neokritosaurid, but findings of living specimens have since confirmed that it had a hollow, semicircular crest.

The jaws have eight teeth on each side that did not form dental batteries. On the underside of the dentary were twenty-six ridges, or "dentary bumps", that are present on all cenohadrosaurs. Known as r1 to r26, their true function is unknown, but they may be attachment points for powerful jaw muscles to aid in chewing. Some of these are enlarged to various degrees, and the exact pattern of ridge sizes differs amongst genera, providing useful information for phylogenetic analyses. In *Cenohadros*, r1 is expanded to the second degree (or d2), and r4, r14, r15, r18, r24, and r25 are expanded to d1.

Because the tail of the holotype is incomplete, the exact length of *Cenohadros*initially remained unknown. However, living specimens have revealed that like other neolambeosaurs, it had a 3:25 head-to-body ratio, and with jaws averaging about 40 centimeters (16 inches) in length, *Cenohadros* reached around 3.33 meters (10.9 feet) long.

## Classification

The initial paper of Cancello *et al.* recovered *Cenohadros* as a basal member of the ancient hadrosaurid clade Kritosaurini. Their cladogram is show below:

It was instead later found to be less derived that euhadrosaurs, closely related to Cretaceous South American basal hadrosaurids like *Lapampasaurus* and *Gonkoken*. A cladogram from Aguilar, from the description of Cenohadrosauria and *Crassisaurus*, is shown below:

When more cenohadrosaurs were discovered, *Cenohadros'* precise phylogenetic position within this diverse clade was able to be ascertained. It was initially believed to be a member of the Neokritosauridae, a clade convergent with the extinct kritosaurins, which would make it one of the few dwarf (<4m/13ft) cenohadrosaurs that are not microcenohadrosaurs. A cladogram depicting this hypothesis is shown below:

However, more recent studies have placed *Cenohadros* in the Microcenohadrosauria proper. A cladogram from the latest study is shown below, showing *Cenohadros* within the clade Avirhynchia:

## Biology

Unlike its Cretaceous relatives, *Cenohadros* was a carnivore. It hunted similarly to extinct dromaeosaurids or birds of prey, using its powerful forelimbs to pin down prey while using its thick, reinforced beak to skin the prey alive. Prey choices vary from small mammals like monotremes, multituberculates, and marsupials to larger animals like other cenohadrosaurs.

## References

Note: These sources are a mix of fictional and real publications. Fictional ones will be marked with an asterisk.

1. ↑ 1.0 1.1 1.2 1.3 1.4 \*Cancello *et al.* (date unknown). "Preliminary background of the 'Cenohadrosaur timeline' with the description of a late-surviving non-avian dinosaur." *Annals of the Inter-Temporal and Inter-Universal Commission on Natural History.*
2. ↑ \*Aguilar (date unknown). "A new Cenozoic hadrosaur and the recognition of a new clade of Cenozoic hadrosaurs." *Annals of the Inter-Temporal and Inter-Universal Commission on Natural History.*