Dictionary > Dactylus

Dactylus

Definition
noun, plural: dactyla
(zooanatomy) A dactyl, i.e. a digit (a finger or a toe)
Supplement
The term dactylus refers to a dactyl, which in turn pertains to a digit (i.e. a finger or a toe) of humans, or that which corresponds in other vertebrates. Etymologically, it comes from the Greek word that means finger or dactyl.
In invertebrates, the term dactylus is used to refer to the tip region of the tentacular club of cephalopods (e.g. squid and octopus). The dactylus of the cephalods is narrow. It may be identified by the asymmetrical placement of suckers and the lack of a dorsal protective membrane.1
Dactylus may also pertain to the leg of a decapod crustacean. The leg of crustacean is comprised of seven segments. In their proper order, the segments are named coxa, basis, ischium, merus, carpus, prodopus, and dactylus. Other crustaceans, though, do not conform to this naming system. The dactylus is the seventh (final) segment of thoracic appendages of crustaceans. In certain crustaceans, the dactylus and an outgrowth of the propodus may be fused, forming the claw.2
Word origin: Greek dáktulos (“a finger, a dactyl”)
See also:

  • dactyl

Reference(s):

1 Dactylus. (n.d.). Retrieved from https://en.wikipedia.org/wiki/Dactylus

2 Arthropod leg. (n.d.). Retrieved from https://en.wikipedia.org/wiki/Arthropod-leg


You will also like...

bryophyte - sporophyte and gametophyte
Meiosis and Alternation of Generations

Plants are characterized by having alternation of generations in their life cycles. This tutorial is a review of plant m..

Disturbance on a still water
Abiotic Factors – Water Conditions

A still body of water may be disturbed by a variety of factors. One of them is wind. In fact, it is considered as the pr..

Schematic diagram of DNA replication
DNA Structure & DNA Replication

DNA is a double helix structure comprised of nucleotides. A nucleotide, in turn, is made up of phosphate molecule, deoxy..

Physical growth
Physical Development in Humans

This tutorial elaborates on the physical development of humans, particularly from puberty to adulthood. Read this tutori..

Still Water Animals
Still Water Animals

Animals living in aquatic habitats have diversified and evolved through time. They eventually occupy ecological niches a..

Sensory systems
Sensory Systems

A sensory system is a part of the nervous system consisting of sensory receptors that receive stimuli from the internal ..

Related Articles...

No related articles found

See all Related Topics