An exhaustive study of existing data on the relationship between egg size and maximum size of embryonic shells in 42 species of extant cephalopods demonstrated that these values are approximately equal regardless of taxonomy and shell morphology. Egg size is also approximately equal to mantle length of hatchlings in 45 cephalopod species with rudimentary shells. Paired data on the size of the initial chamber versus embryonic shell in 235 species of Ammonoidea, 46 Bactritida, 13 Nautilida, 22 Orthocerida, 8 Tarphycerida, 4 Oncocerida, 1 Belemnoidea, 4 Sepiida and 1 Spirulida demonstrated that, although there is a positive relationship between these parameters in some taxa, initial chamber size cannot be used to predict egg size in extinct cephalopods; the size of the embryonic shell may be more appropriate for this task. The evolution of reproductive strategies in cephalopods in the geological past was marked by an increasing significance of small‐egged taxa, as is also seen in simultaneously evolving fish taxa.

中文翻译：

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头足类胚胎壳作为重建灭绝类群生殖策略的工具

对 42 种现存头足类动物的卵大小与胚胎壳最大大小之间关系的现有数据进行的详尽研究表明，无论分类学和壳形态如何，这些值都大致相等。卵大小也大约等于 45 种具有基本壳的头足类动物幼体的地幔长度。在 235 种菊科、46 种拟杆菌、13 鹦鹉科、22 种正翅目、8 种巨翅目、4 种癌翅目、1 种 Belemnoidea、4 种Sepiida 和 1 螺旋体中，初始腔室大小与胚胎壳大小的配对数据表明，尽管存在正相关在某些分类群的这些参数之间，初始腔室大小不能用于预测已灭绝头足类动物的卵大小；胚胎壳的大小可能更适合这项任务。