The earliest endosymbiotic worm fossils are known from Late Ordovician rugose (Elias 1986) and tabulate corals (Tapanila 2004) and are preserved as bioclaustrations.
Palaeozoic bioclaustrations are hitherto unknown in cateniform, fasciculate, and auloporoid tabulate corals (Tapanila 2005).
The aim of this paper is to test the following hypotheses: (1) the endosymbiotic worms occurred only in certain host species; (2) the infestation rates are host-specific; (3) endosymbionts preferred a certain type of tabulate morphology (heliolitid versus favositid); (4) the number of infested tabulate species in the coral reef and reef-related community changes over time; (5) the infestation rate of coral species changes with time.
A total of 182 tabulate specimens were collected from 20 Silurian outcrops of Podolia (Fig.
Two endosymbiotic worms were present in the Silurian tabulate corals of Podolia.
The number of infested tabulate species in the Silurian of Podolia increases from one in the Late Homerian to five in the Gorstian, and decreases to two in the Ludfordian (Table 2).
Chaetosalpinx has been interpreted as a tabulate parasite, considering its position between the corallites, perforation of the host's skeleton and soft tissue, modification of its phenotype and possible inhibition of its growth (Zapalski 2007).
In Palaeozoic tabulate corals bioclaustrations are mainly found in common host taxa spanning millions of years of geologic time, e.
Morphological variation of the tabulate coral Paleofavosites cf.
A new endosymbiont in Late Ordovician tabulate corals from Anticosti Island, eastern Canada.