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...

Birth Control and Contraception
Birth Control and Contraception

Different pregnancy and birth control and contraception strategies are described. Read this tutorial to learn each of th..

Neural Control Mechanisms
Neural Control Mechanisms

Neurons generate electric signals that they pass along to the other neurons or target tissues. In this tutorial, you wil..

Energy pyramid
Freshwater Community Energy Relationships – Producers & Consumers

This tutorial looks at the relationship between organisms. It also explores how energy is passed on in the food chain an..

Plant biology
Plant Biology

Plantlife can be studied at a variety of levels, from the molecular, genetic and biochemical level through organelles, c..

Chemical effects on plant growth and development
Effect of Chemicals on Growth & Development in Organisms

Plants and animals need elements, such as nitrogen, phosphorus, potassium, and magnesium for proper growth and developme..

Hominid
The Hominids

The hominid family diversified from the apes around 6 to 8 million years ago. Since then, the evolutionary path has prov..