Kristina Mehlqvist¹ and Jonas Hagström²

¹Department of Earth and Ecosystem Sciences, Division of Geology, Lund University, Sölvegatan 12, SE-223 62 Lund, Sweden

²Department of Palaeozoology, The Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm, Sweden

Email: Kristina.Mehlqvist@geol.lu.se 

Early land plant remains in form of sporangia, with in situ cryptospores, spore masses, and an axis, were identified in the Burgsvik beds on Gotland, Sweden.

 The sporangia are elongate in shape, with fragments of the sporangia wall preserved, and contain well preserved in situ cryptospores. No axes attached to the sporangia were detected. The single axis identified has a superficial longitudinal striation resembling that of epidermal cells and ends in a cup-shaped structure that probably represent the lower part of a sporangium. The spores found within the sporangia were identified as Laevolancis divellomedia and Dyadospora murusdensa.

In the same beds, naked spore masses, most probably representing coprolites of terrestrial arthropods, were found. The spore masses consist of cryptospore monads shrouded in amorphous organic material. These spores are poorly preserved compared to the well preserved dispersed- and sporangia-associated spores, possibly a result of their passage through the digestive system of the animal. The spores in the coprolites were identified as Laevolancis divellomedia, a common local constituent of the dispersed microflora, during this time.

This study represents the first report of the occurrence of definite Silurian land plants in Baltica and one of the earliest evidence for plant-animal interactions in the early terrestrial ecosystems.

POSTER