Earliest known rugosan-stromatoporoid symbiosis from the Llandovery of Estonia (Baltica)

Early symbiotic rugosan endobionts in stromatoporoids from the Rhuddanian of Estonia (Baltica)

“…Similar rugosan–stromatoporoid associations have been described from the Aeronian (two specimens infested of 35) and late Sheinwoodian (three specimens infested of 60) of Estonia (Vinn & Mõtus ; Vinn et al . ). Rugosans are especially common in the stromatoporoids from the Ludlow of Estonia; usually there are numerous rugosan specimens per single stromatoporoid host (Nestor ; Vinn et al .…”

“…Aeronian) appearance of stromatoporoids with a large number of rugosans may indicate increasing host tolerance for rugosan symbionts. The stromatoporoids with symbiotic rugosans seem to be relatively rare in the Llandovery of Baltica (Vinn et al 2015), but they became common in the Ludlow (Nestor 1966, O. Vinn, personal observation). The number of rugosan symbionts per host and number of stromatoporoids with symbionts seem to have increased during the evolution of rugosan-stromatoporoid symbiosis in the Silurian of Baltica.…”

“…Bioimmured rugosans differ from bioclaustrations (Palmer & Wilson 1988) by having their own skeleton. The early symbiotic rugosan endobionts have previously been described from the Aeronian of Baltica (Vinn et al 2015) and Llandovery of Laurentia (Nestor et al 2010). In addition to rugosans, the tabulate coral Syringopora and cornulitids are also common endobiotic symbionts in the Silurian stromatoporoids of Baltica (Kershaw 1987;Vinn & Wilson 2010;Kershaw & Mõtus 2016).…”

“…The early symbiotic rugosan endobionts have previously been described from the Aeronian of Baltica (Vinn et al . ) and Llandovery of Laurentia (Nestor et al . ).…”

New data on the intergrowth of Rugosa-Bryozoa in the Lower Devonian of North Gondwana

“…As in the rugosan-stromatoporoid association (VINN et al, 2015) and rugosan-tabulate association (VINN et al, 2017b) the rugosan corallites are arranged perpendicularly to the growth surface of the bryozoan. The longitudinal section in the association shows that the bryozoan grew by frontal budding and according to CADÉE and MCKINNEY (1994) "the growth of the corallites was nicely balanced, keeping the corallites always at the colony surface".…”