Читать книгу Hadrosaurs - David A. Eberth - Страница 16

Where we have been can be determined by looking at the total curve of ornithopod publications (Fig. 1.1A). Beginning in the 1820s, the number of papers published per decade rises to a high of 15 in the 1870s. It then declines to 4 in the 1890s, and increases again, to 24, in the 1920s. The 1940s see a drop to 7, followed by a persistent, long-term increase to the decade of the 2000s, which is characterized by nearly 200 papers, amounting to almost 2 papers per month!

Before turning to several intrinsic factors, I want to examine three kinds of extrinsic events that may have influenced these numbers and patterns. For possible influences due to world events, the European revolutions of 1848, the American Civil War, World War I, the Russian Revolution, the fall of communism, and the combined Iraq and Afghan wars appear to have no substantial influence on rate of publication, whereas the 1929 stock market crash and the subsequent worldwide financial depression followed by World War II are likely factors in the decline of publication rates in the 1930s and 1940s. Regarding technological influences, there are no great fluctuations in rate of publication for technological events, except for the last two events. It is probably safe to say that the invention of personal computers, particularly laptops (1970s), in combination with the development of the World Wide Web and internet (1990s) made a huge impact on the rate of ornithopod publications. With the initiation of web publishing, this trend is certain to continue. Finally, scientific influences probably account for smaller perturbations in the total curve. For example, the discovery of the Iguanodon assemblage from Bernissart probably accounts for the rise in ornithopod publications during the 1870s and 1880s. The rise in publication rates during the 1910s, 1920s, and 1930s can certainly be attributed to the Great Canadian Dinosaur Rush in Alberta. Finally, as a personal homage, I consider John H. Ostrom’s first monographic publication – his 1961 treatment of the hadrosaurids of North America – to signal the beginning of what has turned out to be a plethora of ornithopod publications to the present day.

1.1. Publication trends on ornithopod dinosaurs. (A) Total publication record of ornithopod dinosaurs from 1820 to 2000 tabulated by decade; (B) Total publications of general taxonomy, functional morphology, phylogeny, and biostratigraphy and taphonomy, tabulated by decade; (C) Total publications in biogeography, paleoecology, soft tissue, growth, and faunistics, tabulated by decade.

Intrinsic factors, on the other hand, are some of the subjects that I am interested in, which also have given Ornithopoda pride of place in the world of dinosaur publishing. General taxonomy and faunistics are the largest contributors to the total sample, whereas the rest have relatively low influence.

General taxonomy (Fig. 1.1B) has as long a history, beginning with the first publication on Iguanodon by Mantell (1825) and early on encompassing the first publication on Hadrosaurus by Leidy (1858). Furthermore, it mirrors fairly well the total publication curve, with a high point of 69 publications during the decade of 2000–2010.

Functional morphology (Fig. 1.1B) has a long, but patchy history, beginning with the publication of Mantell (1848) on the teeth and jaws of Iguanodon. It has never been common, but increases significantly in the 1970s and 1980s, with renewed interest in ornithopod jaw mechanics. Functional morphology has been in decline since this time.

Phylogeny (Fig. 1.1B) also has a long and equally patchy history, beginning with Owen’s (1842) christening of Dinosauria. Thereafter, there is a long hiatus until the 1970s, when we see an irregular publication record reflecting the large impact of cladistics on phylogeny estimates. The 1990s and 2000s indicate an important increase in cladistic studies, peaking near 40 publications.

Biostratigraphy and taphonomy (Fig. 1.1B) have a relatively short history, confined to the period of the 1930s to the present, and within this span only relatively abundant since the 1970s, with the publications of Dodson (1971), Rogers (1990), and Varricchio and Horner (1993). There is a steady increase in biostratigraphic and taphonomic publications from the 1980s to the 2000s, indicative of increased interest in the sedimentological aspects of ornithopod fossils.

Biogeography (Fig. 1.1C) is in its infancy, with its concentration of publications only evident from the 1960s onward. This is roughly the same time as the scientific ascendancy of plate tectonics and phylogenetic systematics, and thus, may be a direct product of these two revolutions in the natural sciences (Sereno, 1997, 1999a, 1999b; Upchurch et al., 2002). Biogeography reaches its zenith in the decade of 2000; in all likelihood it will continue to increase.

Paleoecology (Fig. 1.1C) has a relatively short history. With a few notable exceptions (Mantell, 1844; Nopcsa, 1934), the history of paleoecology papers really began in the 1960s. There has been a steady increase in the number of paleoecology publications since then, to a high of more than 30 publications in the decade of 2000–2010.

Soft tissue (Fig. 1.1C), consisting almost entirely of the study of integumentary impressions, has a reasonable steady and long history, increasing steadily since the 1970s. It is presently on a very large upswing, in large part because of the discovery of exceptionally well preserved specimens (particularly in northeastern China) and a more focused evaluation of variation in integumentary patterns (Bell, this volume).

Growth (Fig. 1.1C) has a very modest history. It has been common only since the 1970s, and appears to be on a steep upswing to nearly a dozen papers for the decade of 2000–2010. This increase probably represents the rise in fossil bone histology studies in ornithopods (e.g., Chinsamy, 1995; Horner et al., 2000).

Finally, faunistics (Fig. 1.1C) has a long history, approximately paralleling general taxonomy and the total curve, at least since the 1860s. Faunistics seems to drop off during the decade of the 2000s, but this downturn should be treated with skepticism because it is almost certainly an artifact of sampling extrapolation. Examples taken from the 1990s and 2000s include Csiki (1997), Ryan and Russell (2001), López-Martinez et al. (2001), and Zhou et al. (2003).