The dactylus is the tip region of the tentacular club of cephalopods and of the leg of some crustaceans (see arthropod leg). In cephalopods, the dactylus is narrow and often characterized by the asymmetrical placement of suckers (i.e., the ventral expansion of the club)[1] and the absence of a dorsal protective membrane. In crustaceans, the dactylus is the seventh and terminal segment of their thoracic appendages. In certain instances the dactylus, together with the propodus, form the claw.[2]
The term dactylus means "finger" in Greek.
References[edit]
- ^ Walla, Graeme. "Comparative Morphology of Cephalopod Armature". The Octopus News Magazine Online. Retrieved 2 February 2024.
- ^ Robin, Ninon; van Bakel, Barry W. M.; Hyžný, Matúš; Cincotta, Aude; Garcia, Géraldine; Charbonnier, Sylvain; Godefroit, Pascal; Valentin, Xavier (27 December 2019). "The oldest freshwater crabs: claws on dinosaur bones". Scientific Reports. 9 (1): 20220. Bibcode:2019NatSR...920220R. doi:10.1038/s41598-019-56180-w. ISSN 2045-2322. PMC 6934782. PMID 31882600.
Cephalopod anatomy | ||||||||||||||
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| Shell |
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| Mantle & funnel |
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| Head & limbs |
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| General |
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Developmental stages: Spawn → Paralarva (Doratopsis stage) → Juvenile → Subadult → Adult • Egg fossils • Protoconch (embryonic shell) | ||||||||||||||
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction