Richard Hofmann

Museum für Naturkunde - Leibniz Institute for Research on Evolution and Biodiversity | MFN · Evolution und Geoprozesse

The Dapingian to Darriwilian Kanosh Formation is one of the most fossiliferous units of the Pogonip Group (Great Basin, western US). It records a critical phase of the so-called Great Ordovician Biodiversification Event (GOBE) during which many marine clades diversified on lower systematic levels. However, a comprehensive palaeoecological analysis...

The impact of mass extinctions on the body sizes of animals has received considerable attention and debate, as to whether the reduced size of post-extinction organisms is due to the selective extinction of large species, absence of large species as a stochastic effect of low-diversity faunas, or a size decrease within surviving genera and species....

Cruziana reticulata is an arthropod‐related ichnospecies that is characterized by a conspicuous net‐like scratch pattern whose initial formation and later preservation require the presence of consolidated substrates in shallow marine fine‐grained bottoms. There are two scenarios in which epifaunal to shallow infaunal benthic organisms may access fi...

Biotic interactions such as competition, predation, and niche construction are fundamental drivers of biodiversity at the local scale, yet their long-term effect during earth history remains controversial. To test their role and explore potential limits to biodiversity, we determine within-habitat (alpha), between-habitat (beta), and overall (gamma...

The Permian deposits of Hydra Island, Greece, have been known for over a century and host some of the best-studied and most diverse invertebrate assemblages of the ancient Paleotethys Ocean. However, until now, no Paleozoic fossils of jawed vertebrates had been reported from Greece. Recent fieldwork on Hydra Island brought to light rare cartilagino...

This paper compares the relative contributions of within-habitat diversity [alpha-diversity] and between-habitat-diversity [beta-diversity] to regional diversity [gamma-diversity] in marine benthic communities of the western US before and after the end-Permian mass extinction. We found that presumably cool-water faunas from the Permian Gerster Lime...

Ichnologic approaches have been key to the understanding of causes and consequences of the end-Permian mass extinction event ever since researchers began to focus on this pivotal episode in the history of life. Trace-fossil occurrences or absences have proven useful to recognize the loss in biodiversity and ecologic function during the extinction e...

Changes of community structure in response to competition usually take place on timescales that are much too short to be visible in the geological record. Here we report the notable exception of a benthic marine community in the wake of the end-Permian mass extinction, which is associated with the microbial limestone facies of the earliest Triassic...

The Lower Triassic Mineral Mountains area (Utah, USA) preserves diversified Smithian and Spathian reefs and bioaccumulations that contain fenestral-microbialites and various benthic and pelagic organisms. Ecological and environmental changes during the Early Triassic commonly are assumed to be associated with numerous perturbations (productivity ch...

The end-Permian mass extinction resulted in the most dramatic degradation of marine bottom communities during the Phanerozoic. One result of this extinction was the long-recognized, extreme reduction in bioturbation of the Early Triassic seafloor. Several lines of evidence (i.e., preferential preservation of epifaunal and very shallow-tier infaunal...

The Lower Triassic Werfen Formation of northern Italy represents an important archive for Early Triassic ecosystems. Based on quantitative community analysis using species level identifications, we reconstruct the recovery of benthic ecosystems after the end-Permian mass extinction throughout this unit. The analysis of benthic macrofossil communiti...

Based on the quantitative community analysis using species-level identifications, we track the restoration of benthic ecosystems after the end-Permian mass extinction throughout the Lower Triassic of the western USA. New data on the palaeoecology of the Thaynes Group and Sinbad Formation are provided, which fill a gap between the recently studied p...

Quantitative analyses of the taxonomic composition and palaeoecology of five Early Devonian faunules (earliest Lochkovian to early Emsian) collected from the locality Jebel Ouaoufilal in the Tafilalt (Morocco) were conducted. We examined 3376 specimens belonging to 158 species and their stratigraphic distribution. The quantitative data sets were an...

The end-Permian mass extinction is widely accepted to have been the greatest biotic crises in the history of meatzoan life. The understanding of the subsequent recovery during the Early Triassic is of utmost importance to address fundamental question in earth system science: (i) how do ecosystems respond to large-scale environmental stress, (ii) ho...

The Dinwoody Formation of the western United States represents an important archive of Early Triassic ecosystems in the immediate aftermath of the end-Permian mass extinction. We present a systematic description and a quantitative paleoecological analysis of its benthic faunas in order to reconstruct benthic associations and to explore the temporal...

The Hanneh Member (Cambrian Stage 5) of the Burj Formation and the Umm Ishrin Formation of Jordan represent a transgressive-regressive succession that contains twenty-eight ichnotaxa, including vertical burrows (Arenicolites isp., Diplocraterion isp., Gyrolithes polonicus, Rosselia isp., Skolithos linearis, escape trace fossils), horizontal simple...

The middle Cambrian Hanneh Member of the Burj Formation and the middle to upper Cambrian Umm Ishrin Formation of the Dead Sea area, Jordan, contain well-preserved and abundant ichnofaunas. Trace fossils are present in a wide variety of depositional environments, from tide-dominated shelf to prodelta, delta front and interdistributary-bay tidal flat...

The Spathian (late Early Triassic) Virgin Formation of south-western Utah (U.S.A.) yields a comparatively diverse benthic fauna that flourished ~2 Ma after the end-Permian mass extinction. In this study, we present quantitative palaeoecological data, which are analysed in the context of their depositional environments. This integrated approach help...

Recovery from the devastating Permian-Triassic mass extinction about 252 million years ago is usually assumed to have spanned the entire 5 million years of the Early Triassic epoch. The post-crisis interval was characterized by large-scale fluctuations of the global carbon cycle and harsh marine conditions, including a combination of ocean acidific...