Nodosauridae

Live reconstruction of Edmontonia

  • North America
  • Europe
  • Asia?

The Nodosauridae ("nodes lizards " ) are one of the two subtaxa ( subgroups ), is classified in the group of dinosaurs Ankylosauria.

Features

The Nodosauridae like all Ankylosauria a broad, massive trunk, which is supported by four short, powerful limbs, the hind legs are longer than the front legs. As they were all Ankylosauria quadrupede, the limbs were somewhat lighter than those of the Ankylosauridae, the second sub- group in general. The neck, the trunk and the top of the tail were covered by an armor of bony plates.

The skull of Nodosauridae was - compared to the Ankylosauridae - built narrower and elongated, and the mouth was pointed. The two bony outgrowths behind the eye socket and cheek were small and round - at the Ankylosauridae they were larger and more pointed. As with all Ankylosauria the teeth were small and leaf-shaped and adapted to a plant-based diet. The top of the skull and sometimes even the eyelids were also provided with a bony armor.

Many Nodosauridae had conspicuous spines in the shoulder region, sometimes on the flanks. There are also differences in the construction of the shoulder blade, which has a conspicuous, gall-like excrescence ( acromion ) exhibited at the Nodosauridae. Another distinguishing feature is that the Nodosauridae unlike many Ankylosauridae had no bony tail club.

Paleobiology

The more pointed mouth suggests that the Nodosauridae were selective in their choice of food and certain plant forms preferred. For defense against predators, they used the bony armor, maybe they have pressed in case of threat to the ground to secure the unprotected belly. The spines probably have less defense than the communication served with conspecifics, possibly in the form of display or in direct confrontations.

How long existed the Nodosauridae and what they inhabited continents, is questionable due to the uncertain assignment of numerous genres. The earliest known representatives may already lived in the Jura, in the Cretaceous Period, the Group achieved its greatest forms and species diversity. Finds the Nodosauridae are known mainly from North America and rare in Europe (and probably also from Asia ). It is conceivable that the Nodosauridae are extinct shortly before the mass extinction of the dinosaurs at the end of the Cretaceous period.

System

The systematics of Ankylosauria is controversial in many areas. This is also due to the fact that many findings are poorly preserved and a clear diagnosis often hardly possible. Will also discuss the affiliation of Polacanthidae or Polacanthinae that are sometimes associated with the Ankylosauridae and sometimes the Nodosauridae. The system described here largely follows Vickaryous M. et al. (2004), for comparison is - where there are deviations - represented the systematics of K. Carpenter or the assignment by the describer in parentheses after the name. ( See also Internal classification of Ankylosauria. )

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