Massive Australian Precambrian/Cambrian Impact Structure Massive Australian Precambrian/Cambrian Impact Structure The Massive Australian Precambrian/Cambrian Impact Structure also known as MAPCIS is a proposed impact structure based upon arguments presented by Daniel P. Connelly at Geological Society of America meetings. Its center is located approximately equidistant between Uluru (Ayers Rock) and Mount Conner in Australia's Northern Territory. The structure is approximately in diameter. However, a hypothetical outermost ring in diameter is claimed to be the result of undefined far field stresses. Connelly argues that the age of this hypothetical impact is approximately 545 mya which puts it just before the Cambrian explosion (542 mya) of the
Long branch attraction a wider, fast evolving group, those branches may be misinterpreted as closely related. As such, "long branch attraction" can in some ways be better expressed as "branch length attraction". However, it is typically long branches that exhibit attraction. The recognition of long-branch attraction implies that there is some other evidence that suggests that the phylogeny is incorrect. For example, two different sources of data (i.e. molecular and morphological) or even different methods or partition schemes might support different placement for the long-branched groups. Hennig's Auxiliary Principle suggests that synapomorphies should be viewed as de facto evidence of grouping unless there