Trypanites

Classification
Ichnofossil
Ichnogenus: Trypanites Mägdefrau, 1932

Taxonomic Details

Ichnospecies: (Holland, UGA Strat Lab)

  • Trypanites weisei (Mägdefrau) – Sack-shaped borings of circular cross-section; common in walls of solitary corals – Whitewater, Liberty

Stratigraphic Occurrences

Geographic Occurrences

Stratigraphic Description

Sequences (Formations)

  • C5 Sequence (Whitewater, Liberty)

Identification in Hand Sample

  • General morphology: Closely spaced straight to slightly curved cylindrical tubes, borings
  • Branching: None
  • Surface ornamentation: None
  • Fill: None
  • Lining: None
  • Spreiten: None

Paleoenvironmental Parameters

  • Substrate: Hardground
  • Oxygen content: Low-high
  • Nutrient content: Low-high
  • Energy: Low-high

Interpretations

  • Behavior: Dwelling and feeding
  • Tracemaker: Worm

Potential Environments

  • Shallow to deep marine

Trypanites from the Richmond Group of Southgate, Indiana (CMC 70781)

Published Description

Hasiotis (KU, 2013):

  • Description: Closely spaced straight to slightly curved cylindrical tubes; bulbous terminations are possible but uncommon.
  • Interpretation: Dwelling and feeding trace of a filter-feeding organism in hardground media; indicative of hardground media in shallow to deep marine settings; marine worms.

Fossils of Ohio (1996):

  • Trypanites is a cylindrical boring ranging in width from about 1 to 2 mm, it is longer than wide. This boring is typically found in vertical positions in hardgrounds, but may be perpendicular or parallel to the surface of corals and other thick shelled organisms. Trypanites is probably the most common boring in Paleozoic rocks. It is very common in Ordovician rocks of Ohio, where it can be found as borings into fossil brachiopods, bryozoans, and corals, as well as hardgrounds. It is particularly common in rugose corals, such as the common Ordovician coral Grewginka. Trypanites also is found in Middle Devonian marine organisms. Trypanites was probably made by filter feeding polychaete annelid worms.

Pemberton, et al. (1980):

  • The borings are narrow, elongate, cylindrical structures, the majority of which are straight or gently curved or bent at angles of 120* to 160*, commonly near the opening. They expand gradually downward and end in hemispherical to hemiellipsoidal terminations. The length of individual borings ranges from a few mm to over 6 cm. The average length is 1.4 cm; the average width is 0.18 cm. Many of the borings show branching interpenetrations and cross-cutting by adjacent borings. Most of the branches appear to have resulted from invasions of the initial boring by larval or juvenile borers. Such an origin suggested by the variation in branch lengths and diameters compared to initial boring. Branches display an average length of 0.6 cm and an average width of .06 cm. This size differentiation rules out the possibility of bifurcation since branches caused by one individual borers should be more uniform in size.
  • Measurements of the size and shape of the borings were made in order to quantitatively describe the morphology. Two different populations (here referred to as morphotypes A and B) are differentiated on the basis of the ratio of the length to diameter of the cap. Cap type A is defined as nearly perfect half-circle (D= 0.50 N); whereas type B id elongated in the D direction (D = 0.80 N). The separation of the two morphotypes was made at D = .65 N, which is the mean for the 37 specimens. The two populations contained 16 and 21 specimens, respectively. The table in Text-fig. 1 presents the empirical data relating dimensions of a boring to a percentage of the parameters N or D. For example, given a type A boring with a maximum diameter (N) of 2.0 cm, the diameter of the mouth to the boring (N sub0) should be .56 X 2.0 cm +- 2.4% of 2.0 cm. In general, type A borings show greater variation in diameter. with a rapid increase in diameter to the cap. Type B boring tends to be slightly longer with more constant diameters. One feature not apparent from the model is that in some cases, the N sub0 diameter is greater than the N sub1, indicating an enlargement just at the mouth of the borehole.

Treatise on Invertebrate Paleontology, Part W, Miscellanea Supplement 1 (1975):

  • Description: “More or less straight tunnels, usually vertical, 1 to 2 mm wide, without ramification; closely spaced; occasionally contain excrement of producer.” W. Hantzschel 1975