Science Literature

Until this year, the Bryozoa were missing from the list of Cambrian organisms. Although some had been previously reported, critical scrutiny showed that they were misidentified and that the oldest known bryozoans came from Lower Ordovician strata. This year, however, Upper Cambrian bryozoans were reported from the lower Tinu Formation, southern Mexico. They were said to be about 8 Ma years older than the oldest Ordovician fossils. This means that Cambrian strata can be said to record examples of all the skeletalized metazoan phyla.

"One mineralized group, the phylum Bryozoa, seems to have "missed" the Cambrian radiation. [. . .] As discussed below, Late Cambrian bryozoans are now known, and have features that suggest they lie near the base of the bryozoan lineage."

"Bryozoa", from Ernst Haeckel's Kunstformen der Natur, 1904 (source here)

In view of the ecological perspective this blog has been giving to the appearance of organisms in the fossil record (see here), it is worth highlighting the ecological significance of bryozoans. This is brought out in the following paragraph:

"Bryozoans are an important Paleozoic-Holocene phylum in substrate stabilization, as a food source and major filter-feeding group, as rock formers, and as a component of a new Late Ordovician habitat - animal-constructed reefs. Late Ordovician bryozoan-coral-stromatoporoid reefs were colonized by high-diversity faunas. These reefs replaced earlier, microbially formed, thrombolite reefs. The Tinu Formation shows that Bryozoa, as all other mineralized metazoan phyla, had a Cambrian origin, although Bryozoa formed only small Early Ordovician reefs."

The Cambrian, then was a remarkable period of Earth history. In the Precambrian, we have only soft-bodied organisms. At the end of the Cambrian, we have all the skeletalized metazoan phyla and much more besides. Subsequent periods of Earth history may have had more dramatic radiations at the Order, Class or Family level, but there were no further bauplan innovations affecting skeletalized metazoan organisms.

This phenomenon has long been troubling for the Darwinian paradigm. The branching pattern of speciation endorsed by Darwin and his followers implies that Family, Class, Order and Phylum categories emerge as later stage developments of the evolutionary process. What we see in the fossil record, however, is the opposite of this. We start with discontinuity of body plans, followed by diversification - as variation around a theme. Darwinists have never confronted their theory with the facts - they exhibit all the characteristics of Kuhnian 'normal science' that will force-fit anomalous data to theory. For more on this and the 'inverted cone of diversity', go here.

Cambrian origin of all skeletalized metazoan phyla - Discovery of Earth's oldest bryozoans (Upper Cambrian, southern Mexico)
Ed Landing, Adam English and John D. Keppie
Geology, June 2010, 38(6), 547-550 | doi:10.1130/G30870.1

Abstract: Exquisite Pywackia baileyi Landing n. gen. and sp. specimens from the lower Tinu Formation, southern Mexico, extend the bryozoan record into the Upper Cambrian. They are ~8 m.y. older than the purported oldest bryozoans from South China, and show that all skeletalized metazoan phyla appeared in the Cambrian. The new form differs from similar, twig-like cryptostomes by its shallow autozooecia and an elongate axial zooid, which may be homologous to the stolon in nonmineralized ctenostomes. It may morphologically resemble mineralized stem group bryozoans that retained a stolon-like individual, although an ability to bud was acquired by the feeding individuals (autozooids). The latest Cambrian origin of bryozoans, several mollusk classes (polyplacophorans, cephalopods), and euconodonts was a major evolutionary development and can be considered the onset of the Ordovician radiation of more complex marine communities.