Note on the Holotype of Thallites lichenoides, a Supposed Pennsylvanian Bryophyte

Abstract

Organization of the paleontology collections at the New Brunswick Museum has uncovered the holotype of Thallites lichenoides (Matthew) Lundblad, a supposed Pennsylvanian bryophyte from New Brunswick. The specimen, one of the few reported Paleozoic bryophyte fossils from North America, is poorly preserved and needs to be re-evaluated in future reviews of Paleozoic bryophytes. The Pennsylvanian fossil, Thallites lichenoides (Matthew) Lundblad, has been included in reviews of Paleozoic bryophytes (Schuster 1966; Miller 1980; Krassilov Schuster 1984; Oostendorp 1987) and is listed among rare occurrences of Pennsylvanian thalloid plants in North America (DiMichele & Phillips 1976; Miller 1980). Matthew (1907) originally described the specimen as Rhizomorphia lichenoides, a possible Devonian lichen or fungus. He later considered the Fern Ledges fossil assemblage to be Silurian (Matthew 1910). Stopes (1914, p. 72) established the Pennsylvanian age of the fossil but, unable to examine the specimen, thought it most unlikely that it is either a Thallophyte or a Lichen, suggesting it was more likely a fern aphlebia, an anomalous pinna on a frond rachis. Lundblad (1954) assigned Rhizomophia lichenoides to the form genus Thallites, used by Walton (1925) for plants exhibiting thalloid form, but of unknown affinity. Although Lundblad (1954) suggested it might be a xeromorphic hepatic related to Riccia, Schuster (1966) saw little merit in reaching this conclusion based on the nature of the material. Oostendorp (1987) followed Lundblad's classification, but did not record a location for the type specimen. It is unlikely that anyone in recent years has examined the holotype which has been warehoused in an uncatalogued part of the New Brunswick Museum collection. Matthew's holotype was discovered during recent organization of fossil collections. As with many of the compression fossils from the Fern Ledges locality, T. lichenoides is poorly preserved and may ultimately defy identification. THALLITES LICHENOIDES (Matthew) Lundblad, Svensk Botanisk Tidskrift 48: 406. 1954.