Small shelly fossils (SSFs) are highly informative of the ‘Cambrian explosion’. Their palaeobiodiversity has been documented from lower Cambrian deposits worldwide but it remains elusive in areas such as Iran, despite this region occupying a critical position on north-western Gondwana margin during early Cambrian. This new study SSFs northern Iran provides large dataset understudied area. We re...

Sessile epibenthos were diverse and played important part in the process of energy flow Cambrian marine ecosystem. Based on new specimens from Gaoloufang Section Wulongqing Formation, we describe two representatives group that show character traits with cnidarians bryozoans. If confirmed, material can help us understand origin early evolution these phyla. The discovery more sessile suggests ben...

Sedimentation in the Lowermost Cambrian of China A. Braun, J.-Y. Chen, D. Waloszek & A. Maas Institute of Palaeontology, University of Bonn, Nussallee 8, D-53115 Bonn, Germany. E-mail: [email protected] Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, Nanjing 210008, China University of Ulm, Section for Biosystematic Documentation, Helmholtzstrasse 20, D-98081 Ulm, Ge...

The Cambrian explosion of life was a relatively short period approximately 540 Ma that marked a generalized acceleration in the evolution of most animal phyla, but the trigger of this key biological event remains elusive. Sponges are the oldest extant Precambrian metazoan phylum and thus a valid model to study factors that could have unleashed the rise of multicellular animals. One such factor ...

The early Cambrian Guanshan biota of eastern Yunnan, China, contains exceptionally preserved animals and algae. Most diverse and abundant are the arthropods, of which there are at least 11 species of trilobites represented by numerous specimens. Many trilobite specimens show soft-body preservation via iron oxide pseudomorphs of pyrite replacement. Here we describe digestive structures from two ...

Two characters are stratigraphically compatible if some phylogenies indicate that their combinations (state-pairs) evolved without homoplasy and in an order consistent with the fossil record. Simulations assuming independent character change indicate that we expect approximately 95% of compatible character pairs to also be stratigraphically compatible over a wide range of sampling regimes and g...