Most tunifilids are not hard to identify once a few characters are known. Below are the characters that can generally yield a confident identification:

• Number of cores
• Width (cm)
• Ridge (caused by core) present on one side or both sides
• Material (e.g. paper, plastic)
  • Markings or striations may be present on the membrane or wings.
• Cross section (use scissors to cut off a little nub at the end to expose fresh, undamaged tissue)

Generally, the only numerical value required for casual identification is the width.

Tunifilids are not classified based on color, as there is great variation in color and patterning within species. They are also not classified based on length or host, although some species may be more commonly found in certain lengths or associated with certain hosts.

Ecology and distribution information listed on species descriptions is not limiting, many tunifilids are polyphagus and geographical data is often incomplete.

Number of cores

Tunifilids are split into two orders: Monotunifilida and Polytunifilida. As the names suggest, monotunifilids always have one core and polytunifilids always have more than one core. Currently, all polytunifilids have observed to only have two cores at most.

Some juvenile tunifilids are sometimes attached to neighboring individuals, either fully fused or partially fused. These conglomerates are not polytunifilids.

Width (cm)

While width is not required for the identification of species, it can be used to identify subspecies. Tunifilids are not described off width alone in order to account for variation. Subspecies, however, may be described off of width alone.

Monotunifilids may have a core that is not centered. This is not a reliable method of identification and can vary between individuals of the same species or even within a single individual.

Presence of ridge(s)

A ridge (or ridges in polytunifilids) may be present due to membraned padded around a core. As stated above, the alignment of the central ridge is not a reliable character for monotunifilid identification. Polytunifilids may have ridges that are at the margins (e.g. Margicora), or adjacent to each other (e.g. Pseudodipapyra). Tunifilid ridges may possess markings, segmentation, or be flattened and enlarged. These are important characters.

Another important character concerning ridges is whether they are present on both sides of the body or only one (e.g. Crassifilum vs. Hemicristatum). In the case that the ridge is present on only one side, that side is the “superior side”, and the side without a ridge is the “inferior side”.

Material

The membrane coating the core(s) of tunifilids are generally composed of either paper, plastic, or both. There are two primary categories of plastic-coated tunifilids: Those with a non-pliable, thin, and often transparent or metallic membrane, and those with a pliable, thick, and often waxy membrane. Some monotunifilids may also contain a complete membrane of plastic, with an additional paper membrane on one side. Sometimes, texture of the membrane may be of significance (e.g. smooth/shiny vs. matte/rough).

“Wings” are extensions of the membrane past the central core. In polytunifilids with cores not adjacent to each other, the membrane between cores is termed the “central membrane”. Striations may also be present on the wings or membranes. Wings may be completely absent, as in Acrista or Margicora.

Cross Section

A cross section is of high importance, especially in groups such as Diplastidae. The best method to get a good cross section is to use scissors to trim a little bit off the end of a specimen to expose undistorted, unweathered tissue. The exposed cross section can be examined with a magnifying loupe (jeweler’s loupe) or magnifying glass.