Cephalopod embryonic shells as a tool to reconstruct reproductive strategies in extinct taxa

  title={Cephalopod embryonic shells as a tool to reconstruct reproductive strategies in extinct taxa},
  author={Vladimir L. Laptikhovsky and Svetlana V. Nikolaeva and Mikhail A. Rogov},
  journal={Biological Reviews},
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… 

A phylogenetic approach to understand the evolution of reproduction in coleoid cephalopods.

Macroevolutionary Trade-Offs and Trends in Life History Traits of Cephalopods Through a Comparative Phylogenetic Approach

The robust inverse relationship between fecundity and egg length indicates that cephalopods evolved a directional selection that favored an increase of fecundities and a reduction of egg length in larger species, or an increase in egg length with the concomitant reduction of fecondity and body length in order to benefit offspring survival.

Evolution of reproductive strategies in coleoid mollusks

This study subdivides the early ontogenetic shells of phragmocone-bearing coleoids (belemnoids, spirulids, and sepiids) into key architectural stages and describes their reference to the hatching event, finding that production of small pelagic hatchlings and thus small eggs was the dominant reproductive strategy within the Coleoidea.

Spatial distribution of oncocerid cephalopods on a Middle Devonian bedding plane suggests semelparous life cycle

A mass-occurrence with common preservation of pairs of late Givetian (Middle Devonian) oncocerid cephalopods from Hamar Laghdad in the Tafilalt (eastern Anti-Atlas, Morocco) shows that the pairwise clustering is significant, while ammonoids on the same bedding plane reveal a more random distribution.

Early ontogenetic growth stages of Middle Ordovician orthoceratoid cephalopods from Bohemia

The studied collection includes twelve specimens assigned to the species Bactroceras sandbergeri and shows that the morphological variability in early ontogenetic growth stages of this species was rather low, supporting the previously postulated trend of decreasing the eggand hatchling sizes in orthoceratoid cephalopods from mid-Ordovician times onwards.

Endocerids: suspension feeding nautiloids?

  • A. Mironenko
  • Environmental Science, Geography
    Historical Biology
  • 2018
A new hypothesis is proposed and debated: according to it, the endocerids were planktotrophic cephalopods and the largest of them were giant suspension feeders.

Recent advances in heteromorph ammonoid palaeobiology

An improved understanding of heteromorph ammonoid palaeobiology is reached, linking their small hatchling sizes, planktotrophic diets, and higher metabolic rates than in nautilids, which survived the K/Pg mass extinction event.

The old and the new plankton: ecological replacement of associations of mollusc plankton and giant filter feeders after the Cretaceous?

It is suggested that similar niches occupied in the Cretaceous by juvenile ammonites and belemnites were vacated during the extinction and later partially filled by holoplanktonic gastropods.



Biology of early life stages in cephalopod molluscs.

  • S. von Boletzky
  • Environmental Science, Biology
    Advances in marine biology
  • 2003
Investigations into dispersal and recruitment are of particular interest to fishery biology, but they are also important for ecological biogeography.


During the Devonian Nekton Revolution, ammonoids show a progressive coiling of their shell just like many other pelagic mollusk groups, but in at least three lineages, descendants with a closed umbilicus evolved convergently from forms with an opening in the first whorl (umbilical window).

Sympatric speciation drove the macroevolution of fossil cephalopods

The correlation of ammonoid richness with sea levels and the lack of correlation in nautiloids with nonplanktic hatchlings contradict the general theory that animals with planktic embryos or larvae have lower speciation rates and extinction probabilities, and suggests that speciation is a more complicated process than previously thought.


The smallest living cephalopods are coleoids weighing less than 1 gram when adult (the pygmy squid Idiosepius spp., several pygmy species of the genus Octopus), and there are slightly larger species

Flexible reproductive strategies in tropical and temperate Sepioteuthis squids

Evidence suggests that considerable flexibility is inherent in the reproductive strategy of both S. lessoniana and S. australis, to spawn multiple batches of eggs at discrete times throughout the adult life span.

Early Mode of Life and Hatchling Size in Cephalopod Molluscs: Influence on the Species Distributional Ranges

Hatchling size and associated developmental mode and dispersal potential seem to be main influential factors in determining the distributional range of cephalopods.

Worldwide patterns in mode of development in calyptraeid gastropods

A compiled data set of developmental characters for 78 species of calyptraeid gastropods shows strong latitudinal effects in mode of development, the frequency of planktotrophic species decreases with increasing latitude while the proportion of direct developers increases, and a striking latitudinal pattern in the occurrence of nurse eggs.

Pelagic palaeoecology: the importance of recent constraints on ammonoid palaeobiology and life history

Various lines of evidence suggest that different groups of ammonoids had quite different ecologies, but shell shape alone can only give upper constraints on ammonoid capabilities, a matter that needs to be considered when interpreting their diversity and evolutionary history.

An ancient process in a modern mollusc: early development of the shell in Lymnaea stagnalis

A detailed spatial and temporal map of cell movements and differentiation events during early shell development in L. stagnalis is provided to establish a platform for future work aimed at elucidation of the molecular mechanisms and regulatory networks that underlie the evo-devo of the molluscan shell.