Sander P M
Paläontologisches Institut und Museum, Universität Zürich, Switzerland.
Science. 1988 Feb 12;239(4841 Pt 1):780-3. doi: 10.1126/science.3340859.
The first nothosaur (Neusticosaurus sp.) embryo, one of the very few fossil embryos known, provides a rare glimpse at reproduction in extinct reptiles. The specimen from the southern Alpine Middle Triassic (about 230 million years ago) was recognized as an embryo in comparison with an exceptionally large and well-understood sample of juvenile and sexed adult Neusticosaurus sp. The skeleton shows many embryonic features and may well be the smallest fossil reptile known (body length 51 millimeters). It reached only 22% of mean adult length whereas modern reptiles of this size do not hatch before they reach about 30% of mean adult length. The question of ovipary versus vivipary in pachypleurosaurs is discussed in light of the embryo.
首例幻龙（新幻龙属）胚胎是已知的极为稀少的化石胚胎之一，它让人们得以罕见地一窥已灭绝爬行动物的繁殖情况。这个来自阿尔卑斯山脉南部中三叠世（约2.3亿年前）的标本，与大量保存极为完好且已确定性别的新幻龙属幼年和成年个体样本相比，被确认为是一个胚胎。其骨骼呈现出许多胚胎特征，很可能是已知最小的化石爬行动物（体长51毫米）。它仅达到成年个体平均长度的22%，而现代这种大小的爬行动物在达到成年个体平均长度的约30%之前是不会孵化的。本文根据这个胚胎对肿肋龙类的卵生和胎生问题进行了讨论。
