Miragaia

Creature information
Scientific name :	Miragaia longicollum
Time period :	Late Jurassic period
Primary diet :	Herbivore
In the series
Appearances :	The Watering Hole

Miragaia was a type of Stegosaur that appeared in the episode 2 of Dinosaur Revolution where one were shown killed by a Torvosaurus and later a group attacked the same Torvosaurus when it almost stepped on one of the babies. The Miragaia leave with the herds of sauropods to look for food and water, as well as a new safe haven for their offspring.

In The Watering Hole

In the episode The Watering Hole three were shown dead or dying, with one being killed by a Torvosaurus and later a baby Miragaia was eaten by the megalosaur. When the Torvosaurus engaged the Dinheirosaurus, a group of the stegosaur attacked the same Torvosaurus when it almost stepped on one of the babies. At the end of the episode, the Miragaia leave with the herds of sauropods and co.

Physical Characteristics

The total length of Miragaia has been estimated at 5.5 – 6 metres (18-20 ft).[1] In 2010, Gregory S. Paul estimated the length at 6.5 metres, the weight at two tonnes.

The describers established six distinguishing traits. At their very midline, the praemaxillae meet in a small sharp point, set within a larger notch in the snout tip as a whole. The front lower side edge of the praemaxilla protrudes below. At least seventeen cervical vertebraeare present. The neural spines of the middle cervical vertebrae have a notch at their lower front edge immediately above it a process directed to the front. The vertebrae of the middle neck, rear neck and front back possess neural spines that have a transversely expanded upper end. On the neck two rows of triangular bony plates are present that have a lightly convex outer side and a notch at the upper front edge creating a hook.

Discovery

Miragaia is based on holotype ML 433, a nearly complete anterior half of a skeleton with partial skull (the first cranial material for a European stegosaurid). The remains were found after the construction of a road between the villages of Miragaia and Sobral. The rear half of the skeleton was probably destroyed by the roadcut. The fossils were dug up in August 1999 and August 2001.^[2]Among the recovered bones were most of the snout, a right postorbital, both angulars of the lower jaws, fifteen neck vertebrae (the first two, which articulated with the skull, were absent), two anterior dorsal vertebrae, twelve ribs, a chevron, the shoulder bones, most of the forelimbs including a possible os carpi intermedium, a right first metacarpal and three first phalanges; and thirteen bony plates plus a spike. The bones were not articulated but dispersed over a surface of about five to seven metres, though there was a partial concentration of fossils that could be salvaged within a single block.^[2] ML 433 was found in the Miragaia Unit of the Sobral Unit, Lourinhã Formation, which dates to the late Kimmeridgian-early Tithonian (Late Jurassic, approximately 150 million years ago). Octávio Mateus, Susannah Maidment and Nicolai Christiansen named and shortly described Miragaia in 2009. The type species is Miragaia longicollum.

The generic name refers to the village of Miragaia but also is an allusion to mira, "wonderful" in Latin, and Gaia, the Earth Goddess. The specific name means "long neck" from the Latin longus, "long" andcollum, "neck". A partial pelvis (ilium and pubic bone) and two partial dorsal vertebrae from a juvenile individual (specimen ML 433-A) were found at the same location, intermingled with the bones of the holotype, and were also assigned, as a paratype, to M. longicollum. Casts were made of the holotype bones and partially based on these a life-size skeletal model was constructed from polyurethane and polyester resin parts. Alberto Cobos et alii in 2010 noted that all the diagnostic characters of Miragaia longicollum are based on skeletal elements that are absent in the Dacentrurus holotype found in England in layers of about the same age, while all traits that can be compared are shared by both genera. Cobos et alii therefore proposed that Miragaia is a junior synonym of Dacentrurus.

In 2019 however, Costa et alii determined Miragaia to be a destinct genus following the description of a new specimen, while also determining the North American stegosaur Alcovasaurus longispinus to represents a North American species.