Onychomyrmex

Homology Weekly: Clypeus

<i>Tetraponera aethiops</i> worker showing the location of the clypeus in green (Scanning Electron Micrograph, Roberto Keller/AMNH)

Tetraponera aethiops worker showing the location of the clypeus in green (Scanning Electron Micrograph, Roberto Keller/AMNH)

When looking at an arthropod from our vertebrate perspective it is easy to forget that we are looking right at the animal’s skeleton. While our own vertebrate skeleton consists of a series of internal compact pieces with sponge-like cores that support an external layer of muscles and entrails (all nicely wrapped in skin), the reverse is true for arthropods. The arthropod skeleton consists of a series of external plates and hollow tubes that form enclosed spaces within which the internal musculature system attaches1. One consequence of this peculiar body architecture is that most of what we see on the outer surface of this exoskeleton is but a reflection of what is going on on the inside– minute external pits correspond to places where the cuticle folds in to form internal pillars, and innocent looking shallow furrows on the surface are large internal walls where powerful muscles originate. A simple examination of the exoskeleton, therefore, can tell us a lot about particular functions and consequently about an insect’s behavior. › Continue reading

  1. The only enclosed cavity  formed by the skeleton in vertebrates is the cranium, but there are no muscles inside it.
Share/Save

Tags: , , , , , , ,

Homology (Bi)Weekly: Dentiform Labral Setae

Saturday, May 9th, 2009 | Ants, Comparative Anatomy, Homology Weekly, Morphology, Taxonomy | Comments Off on Homology (Bi)Weekly: Dentiform Labral Setae

Red Hot Chilli Peppers? No, dentiform setae in the labrum of <i>Onychomyrmex doddi</i> worker (Scanning Electron Micrograph, Roberto Keller/AMNH)

Red Hot Chilli Peppers? No, dentiform setae in the labrum of an Onychomyrmex doddi worker (Scanning Electron Micrograph, Roberto Keller/AMNH)

Just as the anterior margin of an ant’s cranium can sometimes be armed with rows of dentiform clypeal setae (that is, especially modified hairs), the lid that closes the insect’s mouth called labrum can bear identical structures. The image above shows two of these specialized teeth-like pieces (in red) flanking an empty broad socket where a third piece used to be inserted.

› Continue reading

Tags: , , , , , ,

Homology Weekly: Dentiform Clypeal Setae

Friday, January 16th, 2009 | Ants, Homology Weekly, Morphology | 7 Comments
Anterior part of the head of an Australian <em>Onychomyrmex doddi</em> worker (Scanning Electron Micrograph, Roberto Keller/AMNH)

Anterior part of the head of an Australian Onychomyrmex doddi worker (Scanning Electron Micrograph, Roberto Keller/AMNH)

Among the many interesting features found in members of the subfamily Amblyoponinae is the presence of unique teeth-like structures at the anterior margin of the ant’s cranium. They are arranged in one or two parallel rows, right above the opening of the oral cavity, in a plate called clypeus. › Continue reading

Tags: , , , , , ,

Subscribe: Entries | Comments
And as we discussed last semester, the Army Ants will leave nothing but your bones.
- Tom Waits

Search

Categories