A student syndrome and dynamics

Revisão sistemática e paleobiogeográfica de Trilobitas Phacopida (Homalonotidae e Calmoniidae) do Devoniano das Bacias do Parnaíba e Amazonas, Brasil

“…(Digonus), included B. notica, was characterized by a smooth trapezoidal glabella and straight or slightly concave rostral suture . The morphology of rostral suture as a taxonomic feature was considered of little importance by Sdzuy (1957) and Saul (1965). , who had access 6 to a large collection of B. herscheli from the Emsian/Eifelian Bokkeveld Group in South Africa, confirmed Sdzuy's (1957) and Saul's (1965) conclusions, suggesting that the rostral suture morphology would be rather related to developmental variations.…”

“…The morphology of rostral suture as a taxonomic feature was considered of little importance by Sdzuy (1957) and Saul (1965). , who had access 6 to a large collection of B. herscheli from the Emsian/Eifelian Bokkeveld Group in South Africa, confirmed Sdzuy's (1957) and Saul's (1965) conclusions, suggesting that the rostral suture morphology would be rather related to developmental variations. Cooper (1982: 17) also noted every transition in glabella morphology between the two subgenera among South African…”