basal fulcrum Basal fulcra may precede the median fins or both of the paired and median fins. Basal fulcra may be lanceolate, leaf-like or arrow-like in shape. The series of basal fulcra may be formed by unpaired plus paired elements depending on the fish group. Most teleosts lack basal fulcra. For additional information on basal fulcra see Arratia (2008, 2009). Fulcrum that is large, laterally expanded, paired or unpaired, scale-like, and that precedes the base of a fin. Arratia, G. 2009. Identifying patterns of diversity of the actinopterygian fulcra. Acta Zoologica (Stockholm) 90 (Suppl. 1): 220-235 TAO:0002082 basal fulcra teleost_anatomy fulcrum