Schematic of different possible times of protostomedeuterostome divergence (orange circles), in relation to other events in the late Neoprotoerozoic. In scenario1 there is little incongruence between the fossil record and the time of divergence, which occurs following the second or Marinoan glacial interval. In scenario2, the divergence occurs between the two glaciations, and in scenario3, before the Sturtian glaciation. Both scenarios 2 and 3 imply a much longer missing interval of post-PDA history. A, Middle Cambrian Burgess Shale fauna; B, Lower Cambrian Chengjiang fauna; C, Diverse Ediacaran fauna; D, Doushantuo phosphorite assemblage (with poor age constraints shown by uncertainty in position).

• The name Vernanimalcula does not imply that there is a companion animal of species ernest, genus Worrelli. It means "Small Spring Animal", referring to its appearance after the great thaw of Snowball Earth, after the Marinoan glaciations.
  
• The Snowball Earth hypothesis is a rather controversial idea, supported by geological evidence, that the planet experienced extremely severe climate changes between 600 and 800 million years ago, and that there were periods of extensive glaciation lasting millions of years during that period.
  The diagram to the right illustrates the timing. Vernanimalcula is from the period labeled "D", when the Doushantuo phosphorite assemblage was laid down. It will also help you see where these fossils fall in relation to the Burgess shale (A), the lower Cambrian (B), and the Ediacaran (C).
  This diagram is from a paper by Erwin and Davidson (2002), in which they present models for the divergence of protostomes (P) and deuterostomes (D). In the Chen et al. paper, they clearly come down on the side of lineage (1), in which the protostomes and deuterostomes diverge shortly after the end of the last major glaciation before the Cambrian. They are ambiguous (and rightly so!) about whether Vernanimalcula belongs to the stem group for both protostomes or deuterostomes, or is an ancestor to just one or the other clade.
• Vernanimalcula is very, very rare. They found 10 specimens, but each specimen required examining 5-10 thousand other microfossils. Somebody was working hard, and I hope there are other interesting fossils in the 100,000 other specimens that were examined, that will be described later.
• We're lucky to have these specimens. They, like the embryo fossils that have been found in that region, were preserved by phosphatization, or direct deposition of phosphates on the structures of the original embryo. No one knows how this process works, or under what conditions it operates. Since the pre-Cambrian fauna seem to have all been small, delicate, and soft-bodied, unusual conditions are required to preserve them, and it is not surprising that they are scarce.

Aww, we need more pictures of this nifty animal. Here is a set of closeups of the fossils.

Close-up images of prominent anatomical features of Vernanimalcula guizhouena discussed in text. The scale bar represents 18 µm in A, 32 µm in B, 24 µm in C, and 28 µm in D. SO, Sensory Organ, i.e., external pit; LU, Lumen; PH, Pharynx; MO, Mouth; CO, Coelomic lumen; CW, mesodermal Coelomic Wall; GU, Gut. (A) Detail of collared mouth, multilayered pharynx, and one anterior surface pit. In this image, which is from the holotype specimen (Fig. 1 A), the floor of the pit can be seen to be composed of a specialized concave layer. Note the coelomic wall, which here as elsewhere in these specimens has a thickness of about 5-6 μm. (B) Mouth of a fourth specimen, Q3105, displaying collared mouth and pharynx, ventral view. (C) Lumen of pharynx from a fifth specimen, X10419, secondarily encrusted, but revealing morphology of opening of pharynx into gut similar to that seen in all specimens shown in Fig. 1. (D) Close-up of spaced external pits, interpreted as possible sensory organs, from the same specimen as shown in Fig. 1 B.

Note that at this scale, each of the blocky bricks that we're seeing that make up the structures is almost certainly a single cell. That's how small the whole animal is,and also gives you an idea of the amazing level of detail preserved in the specimens.