据12月19日的《科学》杂志报道说，当今，在超过 90%的鸟类种系中，雄性禽鸟在照顾其后代时扮演着某种角色。现在，研究人员说，这种由父亲照顾后代的倾向实际上是在数百万年之前就已经开始了，它是由鸟类的远古亲族恐龙在其进化时遗传下来的习惯。
David Varricchio及其同僚对恐龙蛋与巢的化石数据以及这些已经绝种的生物的骨结构进行了检测。他们发现，三种特别的恐龙（他们全都与禽鸟密切相关）的雄性都属于仅由雄性来照顾其年幼后代的生物系统。这一对存在于恐龙中的由父系照顾后代的发现表明，这种抚养后代的方法在脊椎动物中具有深植的进化历史；它也意味着这种由雄性为主的繁殖系统发生在飞行起源之前。文章的作者提出，其它形式的双亲照顾，如现在在某些禽鸟中所见的由父母双亲进行照顾的类型一定是在不同的情况下进化而来的。最后，研究人员说，像这样的目标更为集中的研究加上考古学上的幸运发现可能会使人们最终揭露其它的鸟类特征（如鸟类的鸣唱或鸟类的呼吸等）的起源也是传承于某种特别的恐龙。由 Richard Prum撰写的一篇 Perspective对这一发现进行了更为详尽的解释。（生物谷Bioon.com）
生物谷推荐原始出处：
Science 19 December 2008: DOI: 10.1126/science.1163245
Avian Paternal Care Had Dinosaur Origin
David J. Varricchio,1* Jason R. Moore,2 Gregory M. Erickson,3 Mark A. Norell,4 Frankie D. Jackson,1 John J. Borkowski5
The repeated discovery of adult dinosaurs in close association with egg clutches leads to speculation over the type and extent of care exhibited by these extinct animals for their eggs and young. To assess parental care in Cretaceous troodontid and oviraptorid dinosaurs, we examined clutch volume and the bone histology of brooding adults. In comparison to four archosaur care regressions, the relatively large clutch volumes of Troodon, Oviraptor, and Citipati scale most closely with a bird-paternal care model. Clutch-associated adults lack the maternal and reproductively associated histologic features common to extant archosaurs. Large clutch volumes and a suite of reproductive features shared only with birds favor paternal care, possibly within a polygamous mating system. Paternal care in both troodontids and oviraptorids indicates that this care system evolved before the emergence of birds and represents birds' ancestral condition. In extant birds and over most adult sizes, paternal and biparental care correspond to the largest and smallest relative clutch volumes, respectively.
1 Department of Earth Sciences, Montana State University, Bozeman, MT 59717, USA.
2 Department of Geology and Geophysics, Texas A&M University, College Station, TX 77843, USA.
3 Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA.
4 Division of Paleontology, American Museum of Natural History, New York, NY 10024, USA.
5 Department of Mathematical Sciences, Montana State University, Bozeman, MT 59717, USA.
