Skip to content Skip to navigation

Article: Evolutionary trends in the ornamentation of Cambrian solenopleuropsine trilobites

Publication: Palaeontology
Volume: 44
Part: 1
Publication Date: January 2001
Page(s): 131 141
Author(s): J. Javier Álvaro and Daniel Vizcaïno
Addition Information

How to Cite

ÁLVARO, J., VIZCAÏNO, D. 2001. Evolutionary trends in the ornamentation of Cambrian solenopleuropsine trilobites. Palaeontology44, 1, 131–141.

Online Version Hosted By

Wiley Online Library
Get Article: Wiley Online Library [Pay-to-View Access] |

Abstract

A phylogeny of the Cambrian solenopleuropsine trilobites is constructed to evaluate the importance of differential speciation, extinction and developmental constraints in the evolutionary history of the clade. The transformation of the Pardailhania-Solenopleuropsis (Manublesia)-Solenopleuropsis (Solenopleuropsis) lineages occurred during the mid Caesaraugustian-early Languedocian interval, with all measured morphological variables exhibiting continuous and gradual changes. Several evolutionary trends show tendencies towards an increase in tuberculation and its complexity on the anterior part of the cephalon. A mid Caesaraugustian anagenetic tendency is related to the influence of constant environmental conditions, whereas a late Caesaraugustian-early Languedocian cladogenetic tendency seems to have been an adaptative response to unstable environments. The Solenopleuropsinae clade has a well-preserved continuous fossil record over its full biogeographical range in the Mediterranean region. The sympatric evolution in centrally located populations (Mediterranean area) follows the model of phyletic gradualism, whilst a peripheral population in Avalonia gave rise (by allopatric speciation) to a distinct species, characterized by a variation in the relative size of the palpebral lobes, which may be evidence of a parallel evolution in the trends of ornamentation.
PalAss Go! URL: http://go.palass.org/4vp | Twitter: Share on Twitter | Facebook: Share on Facebook | Google+: Share on Google+