''Thalassinoides'' is an

ichnogenus An ichnotaxon (plural ichnotaxa) is "a taxon based on the fossilized work of an organism", i.e. the non-human equivalent of an artifact. ''Ichnotaxa'' comes from the Greek ίχνος, ''ichnos'' meaning ''track'' and ταξις, ''taxis'' meaning ...

trace fossil A trace fossil, also known as an ichnofossil (; from el, ἴχνος ''ikhnos'' "trace, track"), is a fossil record of biological activity but not the preserved remains of the plant or animal itself. Trace fossils contrast with body fossils, ...

used to refer to "dichotomously or T-branched boxworks, mazes and shafts, unlined and unornamented". Facies of ''Thalassinoides'' increased suddenly in abundance at the beginning of the

Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretace ...

. Such burrows are made by a number of organisms, including the sea anemone ''

Cerianthus ''Cerianthus'' is a genus of tube-dwelling anemones in the Family (biology), family Cerianthidae. Members of the genus are found worldwide. They are Predation, predators, scavengers and omnivores. Characteristics Members of this genus do not hav ...

'', ''

Balanoglossus ''Balanoglossus'' is a genus of ocean-dwelling acorn worms (Enteropneusta). It has zoological importance because, being hemichordates, they are an "evolutionary link" between invertebrates and vertebrates. ''Balanoglossus'' is a deuterostome ...

'' and

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

es, but are most closely associated with decapod

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can ...

s of the (former) infraorder

Thalassinidea Thalassinidea is a former infraorder of decapod crustaceans that live in burrows in muddy bottoms of the world's oceans. In Australian English, the littoral thalassinidean ''Trypaea australiensis'' is referred to as the ''yabby'' (a term whic ...

Gallery

Image:Sherborne Thalassinoides 2 large.jpg, ''Thalassinoides'' burrow system in the Sherborne Building Stone (Jurassic, Bajocian) of Dorset, England; slab cut parallel to bedding. Image:Sherborne Thalassinoides section large.jpg, ''Thalassinoides'' burrow system in the Sherborne Building Stone (Jurassic, Bajocian) of Dorset, England; slab cut perpendicular to bedding. Image:UofS Stone Crest.jpg, Thalassinoides burrows give a unique texture to this crest carved from

Ordovician The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. T ...

Tyndall limestone Tyndall Stone is a registered trademark name by Gillis Quarries Ltd. Tyndall Stone is a dolomitic limestone that is quarried from the Selkirk Member of the Ordovician Red River Formation in the vicinity of Garson and Tyndall, Manitoba, Can ...

References

External links

Chuck D. Howell's Ichnogenera Photos
Arthropod trace fossils Fish trace fossils Thalassinidea Paleozoic life of Manitoba {{trace-fossil-stub