Tubulichnium Książkiewicz, 1977

Uchman, Alfred & Wetzel, Andreas, 2024, Sequestrichnia - an ethological category of marine trace fossils recording the collection and stowage of nutritional material within burrows, Comptes Rendus Palevol 23 (22), pp. 325-338 : 328-330

Ichnogenus Tubulichnium Książkiewicz, 1977

( Fig. 2)

Tubulichnium is an oblique to horizontal, unbranched, blindending tube showing some internal organization due to slight vertical shift; the margins are densely lined with ellipsoidal muddy pellets. The sequestration of material, which is then stowed in muddy laminae and pelleted fill, is documented by its composition: it contains c. 1.5% Corg and 20% CaCO 3 compared to c. 1.1% Corg and c. 26% CaCO 3 in the host sediment and 0.7% Corg and 12% CaCO 3 in the overlying mud in the studied Upper Cretaceous to Paleogene specimens ( Uchman & Wetzel 2017). These data point to selective enrichment of organic-rich particles in the burrow. Microbial activity during priming may generate CO 2 that lowers alkalinity and fosters the dissolution of carbonate ( van Nugteren et al. 2009). Although no clear spreite is developed, a partly laminated fill exhibiting local truncations ( Fig. 2B, C) suggests utilization of the stowed material, as in the case of Zoophycos .

TUBULAR OPEN BURROW SYSTEMS