Sample: Research report

[3. Excerpt, Scientific research paper ] In the Maiasaur nests of Montana, John Horner found evidence that dinosaurs were indeed capable of rearing their young. Particularly surprising was the discovery that the babies remained in the nest for quite some time, and did a great deal of growing there (Horner and Weishampel 66). The internal bone structure of both the adult and juvenile Maiasaur is densely riddled with blood vessels and Haversian canals, more closely resembling that of mammals than reptiles, who lack both (Desmond 62). This type of bone, known as plexiform bone, belongs generally to the fastest growing animals, as it shows evidence of continuous deposition (Horner 175). The presence of numerous Haversian canals also indicates a higher growth rate, being the sites which control the exchange of calcium between the skeleton and blood supply (Desmond 62). A greater number of canals facilitates a greater speed of exchange, allowing large warm blooded animals to reach their full weight usually in one year or less, rather than the five to twenty years required by the larger reptiles (Bakker 348). Reptile bone is of the type known as lamellar zonal bone, with few Haversian canals, and distinct growth rings showing a disparity of growth rates between the warm and cold seasons (Horner 175). This histological evidence is supported by the discovery of Hypsilophodont remains in an area of Australia where the polar winters lasted many months. These small herbivores show every sign of having been active in the sub-zero climate, even developing a larger optic lobe for improved vision in the winter darkness (Rich and Rich 36).