By Neil H. Landman, Richard Arnold Davis, Royal H. Mapes
This publication brings jointly foreign scientists who concentrate on present-day and fossil cephalopods, ranging largely from Paleozoic ammonoids to modern octopods. It covers systematics and evolution; tough- and tender half morphology; and ecology, biogeography, and taphonomy. The booklet additionally contains new facts for the life of an ink sac in fossil ammonoids and contours the 1st list of an in-depth research of octopus ecology in Alaska.
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Additional info for Cephalopods Present and Past: New Insights and Fresh Perspectives
D) Ratio of the ventral lirae space/dorsal lirae space (V/D) on the postembryonic shell. Data are given in Appendix 9. chamber, seen most strongly in AMNH 50416 (Fig. 9a). The pattern of midflank distance parallels that of the ventral distance. The dorsal distance, in contrast, decreases slowly from the apical end of the initial chamber to its end. A decrease in the distance between lirae marks the end of the initial chamber in the ventral and midflank data. There are 40–45 lirae on the initial chamber.
There is a decrease at the end of the initial chamber, followed by a very rapid increase in the distance between lirae at the ventral and midflank position and a less rapid increase at the dorsal position. For the remainder of the ammonitella in A. vanuxemi (Fig. 11a), there is a rapid decrease in the distance followed by a more gradual increase, then a leveling off or a slight decrease. Data end just before the end of the ammonitella in both specimens. There are approximately 65 lirae on the ammonitella of the Agoniatitdae.
The Y axis is the measured distance between two lirae given in microns (mm). Data are given in Appendix 5. (C) Ratio of the ventral lirae space/dorsal lirae space (V/D) on the embryonic shell. Data are given in Appendix 4. (D) Ratio of the ventral lirae space/dorsal lirae space (V/D) on the postembryonic shell. Data are given in Appendix 5. 2 Anarcestidae Two specimens from the Anarcestidae were measured, both identified as Latanarcestes sp. (AMNH 46646 and AMNH 50416). The results are presented in 26 Klofak et al.
Cephalopods Present and Past: New Insights and Fresh Perspectives by Neil H. Landman, Richard Arnold Davis, Royal H. Mapes