Yesterday, I wrote about some extinct scorpionflies that scientists think may have fed on the nectar of seed ferns, conifers, and other ancient plants. Now you can get a pretty good idea of what some of these primitive pollinators looked like in this photo album of scorpionfly fossils.

A new study suggests that scorpionflies that lived during the Jurassic Period fed on the nectar-like juices of seed ferns, conifers, and other primitive plants. As the scorpionflies feasted on the sweet liquid from these plants, they may have also acted as animal pollinators—couriers of pollen grains that are vitally necessary to the reproductive cycle of their host plants. If this scenario is true, scorpionflies represent the earliest known animal pollinators.

In general, for plants to reproduce, pollen grains must be transported from the stamen of a flower to the pistil. There are numerous ways that this transfer can take place—pollen can be carried from stamen to pistil by the wind, water, or by animals.

Until now, scientists believed that primitive plants—plants that predated flowering plants—relied mainly on wind for pollination, not on insects. The understanding was that it animal pollination didn't become widespread until flowering plants evolved during the late Cretaceous period (99.6 to 65.5 million years ago).

But that reasoning has now been called into question by Dong Ren of Capital Normal University, Beijing, China and his colleagues. The scorpionfly fossil evidence they present suggests that scorpionflies may have been pollinating plants as early as 167 million years ago, long before animals started pollinating flowering plants during late Cretaceous.

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Photo © Chas53 / iStockphoto.

In today's animal identification challenge, we have a little grey and white bird with a splash of orange on its flanks. This little bird is about 6.5 inches in length with a 9.75 inch wingspan. It is common in mature deciduous forests in the US, east of the Mississippi River. Its song is whistled "peter peter peter peter" and its call is a series of thin nasal notes, "ti ti ti sii sii zhree zhree zhree". The adult has a black forehead, pale cream feathers around the eye, and a blue-gray crest and upper body. It has a splash of rusty orange feathers on its flanks just beneath its wing. This species does not migrate, choosing instead to brave the cold throughout the winter months throughout its range.

Your task is to identify which of the following three birds this species is: nuthatch, tufted titmouse, or chickadee.

After you have cast your vote in this Animal ID Challenge, be sure to check your answer here.

For paper wasps, it pays to have a unique face. That's what Michael Sheehan and Elizabeth Tibbetts of University of Michigan concluded in a recent paper published in the journal Evolution. Their research reveals that paper wasps (Polistes fuscatus) that have distinct facial markings become embroiled fewer aggressive conflicts than those that had facial markings that made them less easily distinguished from fellow wasps.

"It's good to be different, to wear a name tag advertising your identity," said Michael Sheehan.

In previous research, Elizabeth Tibbetts showed that paper wasps are able to recognize each other based on their distinct facial markings. Now, this latest research reveals just how a unique face can help an individual wasps by enabling it to avoid unnecessary confrontations with other wasps.

Tibbets and Sheehan set up experiments in which they modified the facial patterns of wasps and evaluated the aggressive behavior among individuals in the group. Each group had three wasps whose faces they modified to look similar as well as a fourth wasp whose facial markings were distinct from the other three. Tibbets and Sheehan observed that the wasps that were recognizable—those with the unique facial marking—experienced less aggression than those with less distinct markings. They reasoned that if an individual is reconginzed, repeated aggression is not ncessary as previous social interactions have already settled the question of social status.

Photo © Michael Sheehan / University of Michigan.