Chondrites recurvus (Brongniart, 1823)

Subhorizontal branching structure with most of the branches distributed on the convex side of a relatively long curved tunnel. Two orders of primary successive branching are observed and the branching angle is 26◦ − 56◦. The tunnels are about 1 mm wide

Chondrites recurvus (Brongniart, 1828) ) is characterized by branches only at one side of the master branch, all bent in one direction (Uchman, 1998, 1999; Seilacher, 2007); branching occurs up to the 3rd order (Fu, 1991).

Description. Endichnial, horizontal, branched tunnels. The second-order branches arise from the convex side of a strongly curved first-order branch. Short, third-order branches are very rare. The second-order branches are slightly winding, up to 40 mm long. All tunnels are about 1.5 mm wide. They are filled with dark grey argillaceous background sediment.

Remarks. For discussion of this ichnospecies see Fu (1991) and Uchman (1999).