Sprecher
Beschreibung
The first Carex L. fossils from Macaronesian archipelagos were found in 1859, within the 1.3 Ma (Late Pleistocene) Porto da Cruz sediments (PdCs) in Madeira Island. These were described by O. Heer (1809-1883) in 1864, as belonging to two taxa: i) ‘1. Carex?’: based on leaf and isolated achene fossils morphologically similar to “C. myosuroides Lowe”(nom. illeg.), an extant plant recently redescribed as a new Madeiran endemic C. sequeirae Míguez & al., and ii) ‘2. Carex?’: based only on leaf fossils. Later, in 1882 leaf and spike fossils were collected in PdCs but not studied. Since then, Madeiran Carex fossils have been neglected. Here we briefly illustrate and discuss, based on historical and new data, the taphonomy, palaeoecology and palaeobiodiversity of Carex from the Early Pleistocene of Madeira Island. Briefly, the fossils occur as impressions/compressions within a fluvial deposit, locally associated with a lenticular silty limestone layer that covers a palaeosol. Taphonomically, the sedges were growing in the margin of a palaeostream and were quickly buried in situ, allowing their preservation as whole plants or as dispersed organs. Comparison of extant Madeiran native (including endemic) Carex spp. and the fossils, especially the spikes, utricules and achenes using optical microscopy and scanning electron microscopy allowed the preliminary identification of two fossil morphotypes: one aff. C. sequeirae and the other aff. C. lowei Bech., although achenes of the latter are half the size. Additional detailed morphological and anatomical comparison will allow the systematic position of the Madeiran sedge fossils to be disentangled.