scholarly journals The Musculature of Coleoid Cephalopod Arms and Tentacles

2016 ◽  
Vol 4 ◽  
Author(s):  
William M. Kier
Keyword(s):  
Coleoid Cephalopod

New records of coleoid cephalopod jaws from the Upper Cretaceous of Hokkaido, Japan, and their paleobiogeographic and evolutionary implications

2017 ◽  
Vol 70 ◽  
pp. 128-141 ◽  
Author(s):  
Kazushige Tanabe ◽  
Akihiro Misaki ◽  
Yoshinori Hikida ◽  
Tomohiro Nishimura
Keyword(s):  
Upper Cretaceous ◽  
New Records ◽  
Coleoid Cephalopod

scholarly journals Molecular clocks indicate turnover and diversification of modern coleoid cephalopods during the Mesozoic Marine Revolution

2017 ◽  
Vol 284 (1850) ◽  
pp. 20162818 ◽  
Author(s):  
Alastair R. Tanner ◽  
Dirk Fuchs ◽  
Inger E. Winkelmann ◽  
M. Thomas P. Gilbert ◽  
M. Sabrina Pankey ◽  
...  
Keyword(s):  
Molecular Clocks ◽  
Early Mesozoic ◽  
Bony Fishes ◽  
Unique Nature ◽  
Molecular Dataset ◽  
Divergence Estimates ◽  
Mesozoic Marine Revolution ◽  
Marine Vertebrates ◽  
Cephalopod Evolution ◽  
Coleoid Cephalopod

Coleoid cephalopod molluscs comprise squid, cuttlefish and octopuses, and represent nearly the entire diversity of modern cephalopods. Sophisticated adaptations such as the use of colour for camouflage and communication, jet propulsion and the ink sac highlight the unique nature of the group. Despite these striking adaptations, there are clear parallels in ecology between coleoids and bony fishes. The coleoid fossil record is limited, however, hindering confident analysis of the tempo and pattern of their evolution. Here we use a molecular dataset (180 genes, approx. 36 000 amino acids) of 26 cephalopod species to explore the phylogeny and timing of cephalopod evolution. We show that crown cephalopods diverged in the Silurian–Devonian, while crown coleoids had origins in the latest Palaeozoic. While the deep-sea vampire squid and dumbo octopuses have ancient origins extending to the Early Mesozoic Era, 242 ± 38 Ma, incirrate octopuses and the decabrachian coleoids (10-armed squid) diversified in the Jurassic Period. These divergence estimates highlight the modern diversity of coleoid cephalopods emerging in the Mesozoic Marine Revolution, a period that also witnessed the radiation of most ray-finned fish groups in addition to several other marine vertebrates. This suggests that that the origin of modern cephalopod biodiversity was contingent on ecological competition with marine vertebrates.

scholarly journals The retinal topography of three species of coleoid cephalopod: significance for perception of polarized light

2011 ◽  
Vol 366 (1565) ◽  
pp. 724-733 ◽  
Author(s):  
Christopher M. Talbot ◽  
Justin N. Marshall
Keyword(s):  
Cell Density ◽  
Polarized Light ◽  
Potential Significance ◽  
Retinal Topography ◽  
Habitat Differences ◽  
Light Stimuli ◽  
Structure Density ◽  
Horizontal Grid ◽  
Coleoid Cephalopod ◽  
Cell Specialization

The retinal topography of three species of coleoid cephalopod (one cuttlefish, one squid and one octopus) was investigated to examine and compare the structure, density and organization of the photoreceptors. The aim was to determine if there were areas of increased cell density and/or cell specialization that might be related to lifestyle or phylogeny. The orientation of photoreceptors around the curved surface of the retina was also mapped to reveal how the overall arrangement of cell microvilli might enable the perception of polarized light stimuli. It was found that all species possessed an increase in photoreceptor density in a horizontal streak approximately placed at the position of a potential horizon in the habitat. The overall arrangement of photoreceptor microvillar arrangements followed lines of latitude and longitude in a global projection that has been rotated by 90°. This arrangement seems to map polarization sensitivities on the outside world in a vertical and horizontal grid. The potential significance of this and other retinal specializations is discussed in the context of phylogenetic and habitat differences between species.

A new genus of coleoid cephalopod from the Jackson Group (Late Eocene), Hinds County, Mississippi

2010 ◽  
Vol 292 (1-3) ◽  
pp. 53-63 ◽  
Author(s):  
Patricia G. Weaver ◽  
David T. Dockery III ◽  
Charles N. Ciampaglio
Keyword(s):  
New Genus ◽  
Late Eocene ◽  
Coleoid Cephalopod

scholarly journals Trachyteuthis covacevichin. sp., a Late Jurassic Palaeopacific coleoid cephalopod

Fossil Record ◽  
2008 ◽  
Vol 11 (1) ◽  
pp. 39-49 ◽  
Author(s):  
Dirk Fuchs ◽  
Hans-Peter Schultze
Keyword(s):  
Late Jurassic ◽  
Coleoid Cephalopod
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