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A bit of information I came across today in Paleobotany: The Biology and Evolution of Fossil Plants . Arthropleura may have been important for pollination of Medullosa (seed ferns such as Macroneuropteris and Allethopteris). It sounds like one of the lines of evidence is an arthropleura part from Mazon Creek. Interesting.....

Terrestrial arthropods can be traced from the Devonian, with a major explosive radiation taking place during the Pennsylvanian (Rolfe, 1980). Two lines of evidence suggest that at least one of these organisms was perhaps involved in pollination in the medullosan seed ferns. Arthropleura was a millipede-like animal that was the largest terrestrial arthropod during the Carboniferous. It has been suggested that Arthropleura was herbivorous or detritivorous (Rolfe and Ingham, 1967). The animal inhabited the Pennsylvanian Euramerican province and had numerous body segments with complex limbs consisting of many segments (Rolfe and Ingham, 1967). The potential involvement of Arthropleura as a pollinator is based on two lines of evidence. One is the discovery of numerous seed fern pollen grains of the Monoletes type on a leg segment of an animal from the Middle Pennsylvanian (Westphalian D) Francis Creek Shale of northeastern Illinois. Strengthening the possible pollinator role of Arthropleura is the fact that pollen of Monoletes is extremely large (200–550 μ m) and obviously not well adapted to wind dispersal. These independent lines of evidence suggest that Arthropleura may have acted as a pollinator in the Euramerican swamps. What is not known is whether such a pollination system evolved passively through casual contact of a foraging herbivore or whether the earliest biotic pollinators were attracted to the plant by some chemical or morphological cue.

(Taylor, Thomas N; Taylor, Edith L; Krings, Michael (2009). Paleobotany: The biology and evolution of fossil plants. ISBN 978-0-12-373972-8., PAGE 1023)

Edited by Stocksdale
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This is interesting, but makes little sense. The act of pollination by an animal requires it to move pollen from the male fertile structure and deposit it correctly on the female structure. In this case, where we are talking about seed ferns in particular medullosans that would necessitate pollen to be placed inside the pollen tube of a trigonocarpus seed. I imagine this may have somehow occasionally accorded, but not as part of the plants normal life cycle.

What we do know of Arthropleura is they ate lycopsid cones as part of their diet. This is shown in small examples of whole animals from France with lycopsid spores in their gut region and at Mazon Creek where there are very large coprolites made up of ground-up lycopsid bracts (Lepidostrobophyllum). These are assumed to be from Arthropleura from there large size, and the fact Arthropleura is the only know animal which we know of large enough to produce it. A case could be made that this was one means of dispersing lycopsid megaspores (female spores), which pass through the gut freely or still attached to the bases of the female cone bracts.

Hope this helps,

Jack

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Thanks, Jack. You make some good points there.

I also notice that there were no supporting references for the later part of that paragraph where most of the book is full of references.

Edited by Stocksdale
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fossilized6s

I know in the modern ecosystem a lot of plants and trees rely on creatures to ingest their seeds to break them down for fertilization, and ultimately the spreading of the species. This maybe the case here. But i only known mammals to do this....

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Hi Jack and Charlie,

I was thinking about this a bit more. I'm not sure the specific logistics of the medullosan plants, but I'd imagine a millipede (maybe not the large arthropleura) could be used to move pollen to the tube of the trigonocarpus seed. Without some creature helping, the plant would simply be using wind to get the pollen there. And in the book, they think the pollen grains are larger than one would think for wind pollination.

I know of many angiosperms that use ants in such a way. I'll have to look into whether modern millipedes are used for angiosperm pollination in some cases.

Do any gymnosperms ever use insects as pollinators or are they purely wind pollinated. I might have to do some more research into that. Particularly how the cycads and gingko gymnosperms work....

Thanks,
Paul

Edited by Stocksdale
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After a quick search, here's an interesting bit about cycads being pollinated by thrips.

http://news.nationalgeographic.com/news/2007/10/071004-cycad-sex_2.html

Perhaps the Mazon Creek's flying "cockroaches" would be better candidates as pollinators.

Here's a paper about the thrip as a primeval pollinator of cycads.

Thrips: the primeval pollinators?

http://caterpillar.ento.csiro.au/thysanoptera/Symposium/Section6/23-Terry.pdf

Edited by Stocksdale
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But i only known mammals to do this....

It is known from birds also, I belive the dodo(or maybe the elephant bird? Auspex? )was an example. I forget the species of plant, but it almost followed the bird into extinction before it was realized that the seedcoat was so thick that the seed could not rupture it upon germination unless it had been reduced by digestive forces. The seedcoat is now reduced mechanically.

If we really want to ensure the plants survival however, we should be selectively breeding for a thinner seed coat, which would allow it to self propogate, if possible.

fkaa

Hah! Further research has shown that this rare plant, known as the dodo tree, may not have been linked to the dodo, but to other animals, or it may just be a rare plant.

Things you learn but need to be unlearned over the course of a lifetime.

Edited by ashcraft
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It is known from birds also, I belive the dodo(or maybe the elephant bird?...

They were a mechanism for seed dispersal, but probably not pollination.

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They were a mechanism for seed dispersal, but probably not pollination.

Ah! Expanding on a point with incorrect information when I didn't understand the premise. I am ready to start lecturing next week! Fortunatly, it will be chemistry.

fkaa

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Frankly, I think Arthropleura was too big to be clambering about in the canopy of a medullosan forest. Everything about the critter says "ground dweller" to me. The only reason for a creature to adopt an arboreal existence is to avoid predators (of which Arthropleura had none).

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