New Cambrian Fossil: Missing Link?
A weird animal from Chinese Cambrian strata looks like a worm with legs, the whole body studded with spines. Was it on the way to becoming an arthropod? The authors think so, but other members of its group were already known from the Cambrian fossil record.
The “walking cactus” with ten pairs of legs was named Diania cactiformis by the discoverers from China and Germany, publishing in Nature.1 PhysOrg discussed it briefly and National Geographic News included an artist’s conception.
Nature said it was already “derived” (advanced) on the arthropod lineage. The editor’s summary stated, “The possession of what seem to be the beginnings of robust, jointed and spiny legs suggest that this bizarre animal might be very close to the origins of the arthropods.” This was based on phylogenetic analysis, though, not on dating or genetics. It seems similar to other creatures known as Lobopodia, “a group of poorly understood animals” according to Wikipedia, which evolutionists feel might be ancestral to both onycophorans and arthropods; however, “precise classification is still in flux.”
As for its place in the Cambrian explosion, National Geographic said, “It would have lived about 500 million years ago during a period of rapid evolution called the Cambrian explosion.” It was not, therefore, a missing link leading up to the explosion. The authors in Nature said, “How close Cambrian lobopodians are to the ground plan of the arthropod common ancestor remains a point of debate,” and as for its ancestry to arthropods, admitted, “Our new fossils cannot resolve this question in its entirety, but they do demonstrate that appendage morphology was more diverse among Cambrian lobopodians than is sometimes realized.” They emphasized that, “to our knowledge, Diania has the most robust and arthropod-like limbs found in any lobopodian until now.” But added doubt by saying, “However, we should caution that dinocaridids, Diania and other potential stem-arthropods typically express mosaics of arthropod-like characters, which makes resolving a single, simple tree of arthropod origins problematic.”
In fact, their own phylogenetic analysis of Diania put it in a “surprising” position in the evolutionary tree. They entertained the option that it might represent a secondary reduction of more advanced animals like the large predator Anomalocaris; whatever it was, all could agree it was “a highly unusual creature.”
1. Liu, Steiner et al, “An armoured Cambrian lobopodian from China with arthropod-like appendages,” Nature 470 (24 February 2011), pp. 526�530, doi:10.1038/nature09704.
It was a highly unusual creature among many highly unusual creatures, to the extent that the unusual was usual. Simultaneous diversity and morphological disparity is not evolution. Diania is no more advanced or primitive than any of the many other animal body plans from the Cambrian explosion, so this fossil is not going to help solve the evolutionists’ magic act (see 01/07/2011), especially with vertebrates already present in the early Cambrian (01/30/2003). Remember, it’s what’s inside that counts. This creature may have look primitive through Darwinian eyes, but it had the ability to move its limbs, detect food, eat, digest, and reproduce its body. Such things do not happen without a body plan.