Dinosaur Behaviour


Dinosaur behaviour concerned with reproductive activities and life history strategies can be hypothesised from the fossil record through studies of geology and comparative biology. Dinosaurs constructed rimmed earthen nests in which they deposited from 12 to 30 eggs. The eggs were incubated either by rotting vegetation or direct body heat produced by the parent as they brooded the eggs like birds. Dinosaurs nested in colonies like birds, and returned to the same nesting areas on a regular basis. Some hatchling dinosaurs were nest‐bound or altricial, and were brought food by their parents. These kinds of baby dinosaurs grew very fast in the confines of their nests. Gigantic accumulations of dinosaur skeletal remains indicate that many dinosaurs, particularly the ceratopsians and hadrosaurs lived in large aggregations or herds and may have migrated to find food. The skulls of many dinosaurs possess elaborate bony structures including horns, spikes, domes and shields that have been interpreted as defensive features. Recent studies showing that these features change shape during growth suggest that they are actually for species recognition, particularly so that the adults could recognise juveniles and the juveniles could recognise adults. Nesting grounds, large accumulations of skeletons and cranial display features all indicate that dinosaurs were very social animals.

Key Concepts:

  • Dinosaurs laid eggs in nests and lived in colonies.

  • Plant‐eating dinosaurs may have incubated their eggs using rotting vegetation.

  • Meat‐eating dinosaurs incubated their eggs by sitting on them, much like birds.

  • Some dinosaurs cared for their young by bringing them food.

  • Dinosaurs, particularly hadrosaurs and ceratopsians, travelled in gigantic herds.

  • The horns and spikes and shields found on the skulls of dinosaurs were most likely used for species recognition rather than defence.

Keywords: altricial young; dinosaurs; eggs; nesting; precocial young; herds; hierarchies

Figure 1.

Side views of a Triceratops growth series. (a–c) Juveniles with orbital horns that arc backward and triangular bones on the back edges of their shields. (d) A small subadult showing the orbital horns growing forward, and (e) a large subadult with forward pointing orbital horns. (f) A full‐grown adult showing forward pointing horns and a large hole in its shield, probably for weight reduction. (f) used to be called Torosaurus.

Figure 2.

Troodon brooding its eggs. Reproduced with permission from Horner . Copyright by Annual Reviews.



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Further Reading

Carpenter K, Hirsch K and Horner JR (eds) (1994) Dinosaur Eggs and Babies, 1st edn. Cambridge: Cambridge University Press.

Dodson P (1975) Taxonomic implications of relative growth in lambeosaurine hadrosaurs. Systematic Zoology 24: 37–54.

Horner J (2002) Evidence of dinosaur social behavior. In: Scotchmoor JG, Springer DA, Breithaupt BH and Fiorollo AR et al. (eds) Dinosaurs, the Science Behind the Stories, pp. 71–77. Alexandria, VA: American Geological Institute.

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How to Cite close
Horner, John R(Nov 2012) Dinosaur Behaviour. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0003318.pub3]