Feather stars (aka crinoids)
Underside of a starfish(More below the fold)
The fossils represent compound eyes -- the multi-faceted variety seen in arthropods such as flies, crabs and kin -- and are amongst the largest to have ever existed, with each eye up to 3 cm in length and containing over 16,000 lenses.
The number of lenses and other aspects of their optical design suggest that Anomalocaris would have seen its world with exceptional clarity whilst hunting in well-lit waters. Only a few arthropods, such as modern predatory dragonflies, have similar resolution.
The existence of highly sophisticated, visual hunters within Cambrian communities would have accelerated the predator-prey 'arms race' that began during this important phase in early animal evolution over half a billion years ago
Over millions of years, changes to our vocal organs have allowed us to produce a rich mix of sounds. One such change was the loss of the air sac - a balloon-like organ that helps primates to produce booming noises.
All primates have an air sac except humans, in whom it has shrunk to a vestigial organ. ...To find out how this changed the sounds produced, Bart de Boer of the University of Amsterdam in the Netherlands created artificial vocal tracts from shaped plastic tubes. Air forced down them produced different vowel sounds, and half of the models had an extra chamber to mimic an air sac.De Boer played the sounds to 22 people and asked them to identify the vowel. If they got it right, they were asked to try again, only this time noise was added to make it harder to identify the sound. If they got it wrong, noise was reduced.He found that those listening to tubes without air sacs could tolerate much more noise before the vowels became unintelligible.The air sacs acted like bass drums, resonating at low frequencies, and causing vowel sounds to merge...Observations of soldiers from the first world war corroborate de Boer's findings. Poison gas enlarged the vestigial air sacs of some soldiers, who are said to have had speech problems that made them hard to comprehend.
[above] The fairy wasp, Megaphragma mymaripenne... pictured next to a Paramecium and an amoeba at the same scale.From Not Exactly Rocket Science.
As they get smaller, insects can do away with many of their organs. The feather-winged beetles – twice as big as the fairy wasps, but still impressively tiny – have drastically reduced the size of their genitals, guts and breathing tubes. They have totally lost their hearts: at their size, diffusion is enough to carry liquids around their body without the need for a pump. Their wings, like those of thrips and fairy wasps, are little more than wispy strands, rather than the flat oars of most other insects. That’s all they need to paddle through thick air currents.
From early childhood on, children frequently use distinct gestures to draw the attention of adults to external objects. So-called deictic gestures such as "pointing" ("look here") and "holding up of objects" ("take this") are used by children for the first time at the age of nine to twelve months, before they produce their first spoken words. Scientists believe that such gestures are based on relatively complex intelligence abilities and represent the starting point for the use of symbols and therefore also human language. Deictic gestures are thus milestones in the development of human speech.Full story at Science Daily.
Surprisingly, observations of comparable gestures in our closest living relatives, the great apes, are relatively rare. Chimpanzees (Pan troglodytes) in the Kibale National Park in Uganda, for example, use so-called directed scratches, to indicate distinct spots on their bodies to be groomed. Deictic gestures thus represent an extremely rare form of communication evolutionarily and have been suggested as confined to primates only.