長脖子的蜥腳類恐龍可能并非像電影和藝術作品中描繪的那樣是群居的巨獸,。
據(jù)美國《科學》雜志在線新聞報道,，與成群生活不同，一些蜥腳類恐龍——例如阿拉莫龍——可能是一種孤獨的動物,，它們只有在年幼的時候才會短暫地聚集在一起,。
古生物學家在美國蒙大拿州和得克薩斯州發(fā)現(xiàn)了兩個保存完好的恐龍“墓穴”，其中的恐龍全部為年輕個體,。這些小恐龍可能是干旱的犧牲品,，而研究人員在這兩個墓穴中并沒有發(fā)現(xiàn)任何成年蜥腳類恐龍的化石，這意味著小恐龍完全沒有受到大恐龍的照顧,。古生物學家推測,，一些蜥腳類恐龍在成長到能夠自己填飽肚子后便會本能地“離家出走”。
研究人員在即將出版的《古地理學,、古氣候?qū)W,、古生態(tài)學》雜志上報告了這一研究成果。（生物谷Bioon.com）
生物谷推薦原始出處：
Palaeogeography, Palaeoclimatology, Palaeoecology,，doi:10.1016/j.palaeo.2009.01.002 ,，Timothy S. Myers,，Anthony R. Fiorillo
Evidence for gregarious behavior and age segregation in sauropod dinosaurs
Timothy S. Myersa,and Anthony R. Fiorillob
aHuffington Department of Earth Sciences, Southern Methodist University, Dallas, TX 75275, United States
bMuseum of Nature and Science, P.O. Box 151469, Dallas, TX 75315, United States
Abstract
Both body fossil and ichnofossil evidence for gregarious behavior in sauropod dinosaurs is examined. Some localities suggest that herds were partitioned on the basis of age, whereas other sites reveal groups consisting of both adult and juvenile/subadult individuals. Two skeletal accumulations showing evidence of age segregation are examined in detail. The Mother's Day Quarry in the Upper Jurassic Morrison Formation of Montana contains the remains of several immature diplodocoid sauropods. An assemblage in the Upper Cretaceous Javelina Formation of Big Bend National Park in Texas consists entirely of juvenile Alamosaurus. Both the Mother's Day and Big Bend assemblages are interpreted here as remnants of age-segregated herds. The differences between skeletal accumulations composed entirely of immature animals and mixed-age ichnological assemblages imply that herd composition was variable. When age segregation is recognized, in both fossil and modern taxa, it is thought to minimize the fitness costs related to behavioral synchronization within social groups. Age segregation of herds also contraindicates extended parental care as typical of at least some sauropod taxa.
