Understanding the Great Ordovician Biodiversification Event (GOBE): Influences of paleogeography, paleoclimate, or paleoecology

Abstract

ABSTRACT"The Great Ordovician Biodiversification Event" (GOBE) was arguably the most important and sustained increase of marine biodiversity in Earth's history. During a short time span of 25 Ma, an "explosion" of diversity at the order, family, genus, and species level occurred. The combined effects of several geological and biological processes helped generate the GOBE. The peak of the GOBE correlates with unique paleogeography, featuring the greatest continental dispersal of the Paleozoic. Rapid sea-floor spreading during this time coincided with warm climates, high sea levels, and the largest tropical shelf area of the Phanerozoic. In addition, important ecological evolutionary changes took place, with the "explosion" of both zooplankton and suspension feeding organisms, possibly based on increased phytoplankton availability and high nutrient input to the oceans driven by intense volcanic activity. Extraterrestrial causes, in the form of asteroid impacts, have also been invoked to explain this remarkable event.

Carbonates in Skeleton-Poor Seas: New Insights From Cambrian and Ordovician Strata of Laurentia

“…Nor does it rule out bottom-up proposals that link animal radiation to changing patterns of primary production. Indeed, deep-ocean ventilation might well have facilitated changes in primary production of the kind that Servais et al (2008Servais et al ( , 2009) called upon to explain Ordovician animal evolution. Finally, decreasing metabolic cost of skeletonization does not rule out increasing benefit associated with enhanced predator pressure; the two hypotheses are not mutually exclusive.…”

Palaeozoic evolution of animal mouthparts

“…As far as diversity is concerned, the Cambrian explosion cannot be fully separated from the GOBE (Servais et al 2008(Servais et al , 2009(Servais et al , 2016; both really belong to one giant diversification cycle, interrupted by extinctions in the Cambrian and Ordovician, and subsequently followed by a (somewhat fluctuating) plateau until the Devonian and a decline that started with the Late Devonian climatic changes and mass extinctions and, depending on author and method, a diversity spike in the Permian (e.g. Sepkoski 1978, Alroy 2010b, Smith et al 2012.…”

Integrated “plume winter” scenario for the double-phased extinction during the Paleozoic–Mesozoic transition: The G-LB and P-TB events from a Panthalassan perspective

“…Detailed magnetostratigraphy of the Ordovician is still unknown; however, the ''relatively stable" period called Burskan reversed bias polarity interval (particularly its later part; Algeo, 1996) or Moyero Reverse Superchron (ca. 490-460 Ma;Pavlov and Gallet, 2005) appears concordant with the long-lasting warm period that allowed the rapid diversification of metazoans (e.g., Servais et al, 2009).…”