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Old 08-03-2010, 02:52 PM   #1038437  /  #1
SteveF
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Default Reptilians were the earliest North American pioneers

Cool:

Quote:
Reptiles were the first creatures to venture into continental interiors. That is the conclusion suggested by the oldest reptile prints ever found, some 318 million years old.

The prints were discovered in the tall sea cliffs of the Bay of Fundy in New Brunswick, eastern Canada, by Howard Falcon-Lang of Royal Holloway, University of London, and colleagues. Around five centimetres long, the five-toed prints were made by small gecko-like creatures. "I discovered them by accident when I tripped over," Falcon-Lang says.

Hundreds of stunning footprints belonging to at least three different kinds of reptile have been preserved at the site, all in sediments that, at the time the prints were made, were more than 500 kilometres inland within the supercontinent Pangaea. This makes them the earliest example of creatures living in the harsh dry environment of a continental interior.

Amphibians were the first creatures to make it onto land, hopping up the beach somewhere between 400 and 360 million years ago. But they never ventured far from the coast as they need to lay their eggs in water. Reptiles, with their hard-shelled eggs, faced no such constraint.

"Perhaps the coastal swampy forests were becoming overcrowded and the continental interior were empty spaces just waiting to be filled by pioneers," says Falcon-Lang.
http://www.newscientist.com/article/...-pioneers.html

the paper:

Quote:
Falcon-Lang, H. et al. (2010) Diverse tetrapod trackways in the Lower Pennsylvanian Tynemouth Creek Formation, near St. Martins, southern New Brunswick, Canada. Palaeogeography, Palaeoclimatology and Palaeoecology, advance online.

Newly discovered tetrapod trackways are reported from eight sites in the Lower Pennsylvanian Tynemouth Creek Formation of southern New Brunswick, Canada. By far the most abundant and well-preserved tracks comprise pentadactyl footprints of medium size (3253 mm long) with slender digits and a narrow splay (mostly < 55). Digit lengths typically approximate a phalangeal formula of 23453 (manus) and 23454 (pes), but this may vary due to extramorphology. These tracks are referred to Pseudobradypus and they are attributed to early amniotes. A second type of track (rare) comprises very small (58 mm long) tetradactyl manus, and incompletely preserved pedes. Referred to Batrachichnus, these are attributed to temnospondyl amphibians. A third type (also rare) comprises small pentadactyl pedes (2025 mm long) showing stubby, widely splayed (152) digits with a terminal bulge. Manus are probably pentadactyl (preservation incomplete) with a narrower digit splay. These footprints, classified as Baropezia, are attributed to anthracosaurs. Facies analysis at the most prolific site (179 footprints documented) suggests that the tetrapods lived amongst small alethopterid trees colonizing the abandoned floor of a seasonally active fixed-channel river and a similar dryland context is probable for the seven other sites. The dominance of amniotes in these dryland alluvial facies contrasts markedly with coeval wetland facies in the nearby Joggins Formation, where skeletal and trackway assemblages are amphibian-dominated. This may imply that amniotes were better adapted to seasonally dry settings and sheds new light on the community ecology of tetrapods during a key evolutionary phase.
quite a nice image in the paper:

Quote:


Fig. 11. Reconstruction of the palaeoenvironment and palaeoecosystems represented at the Tynemouth Creek headland site (Copyright, James Robins, 2010). Alethopterid trees, 23 m high, over hang the banks of a Pennsylvanian dryland river channel while a few calamitealeans are rooted here and there on channel bars. Various small tetrapods, inferred from their trackways, foraged in this environment including early amniotes (left, based on Hylonomus), temnospondyls (middle, based on Dendrerpeton) and anthracosaurs (right, based on Calligenethlon). For scale, the Calamites tree in the right foreground is 0.1 m diameter.
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Old 08-03-2010, 03:02 PM   #1038452  /  #2
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Default Reptilians were the earliest North American pioneers

It certainly explains a few US politicians I've seen. Is this intended to legitimise the nativist movement in the Republican Party?
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It's really nice to read something that actually explains some of this stuff in plain English. As opposed to the Reverse Swahili Pig Latin used by most scientists.
(2014) D. Hawkins BSc, Elec. Eng. (Cum Laude) U. Texas Arlington.
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Old 08-03-2010, 03:12 PM   #1038462  /  #3
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Originally Posted by CrocoduckRex View Post
It certainly explains a few US politicians I've seen. Is this intended to legitimise the nativist movement in the Republican Party?
I was going to say lawyers, but politicians is good too.
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Old 08-03-2010, 03:14 PM   #1038464  /  #4
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I love the way they can get so much detail from what I can look at and see nothing but rock with some footprints though
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Old 08-03-2010, 05:06 PM   #1038655  /  #5
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Will read and get right back.
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I suppose it's good for society that I'm not an alpha wolf then.
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Old 08-03-2010, 05:19 PM   #1038673  /  #6
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Quote:
Originally Posted by Abstract
Newly discovered tetrapod trackways are reported from eight sites in the Lower Pennsylvanian Tynemouth Creek Formation of southern New Brunswick, Canada. By far the most abundant and well-preserved tracks comprise pentadactyl footprints of medium size (32–53 mm long) with slender digits and a narrow splay (mostly < 55). Digit lengths typically approximate a phalangeal formula of 23453 (manus) and 23454 (pes), but this may vary due to extramorphology. These tracks are referred to Pseudobradypus and they are attributed to early amniotes. A second type of track (rare) comprises very small (5–8 mm long) tetradactyl manus, and incompletely preserved pedes. Referred to Batrachichnus, these are attributed to temnospondyl amphibians. A third type (also rare) comprises small pentadactyl pedes (20–25 mm long) showing stubby, widely splayed (152) digits with a terminal bulge. Manus are probably pentadactyl (preservation incomplete) with a narrower digit splay. These footprints, classified as Baropezia, are attributed to anthracosaurs. Facies analysis at the most prolific site (179 footprints documented) suggests that the tetrapods lived amongst small alethopterid trees colonizing the abandoned floor of a seasonally active fixed-channel river and a similar dryland context is probable for the seven other sites. The dominance of amniotes in these dryland alluvial facies contrasts markedly with coeval wetland facies in the nearby Joggins Formation, where skeletal and trackway assemblages are amphibian-dominated. This may imply that amniotes were better adapted to seasonally dry settings and sheds new light on the community ecology of tetrapods during a key evolutionary phase.
Paper is here.
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I suppose it's good for society that I'm not an alpha wolf then.
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Old 08-03-2010, 09:18 PM   #1039234  /  #7
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I have opinions on this paper. I will post them in a bit when I've finished digesting it.
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Old 08-03-2010, 09:20 PM   #1039238  /  #8
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Very disappointed that this paper isn't about Zeta Reticulans.
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Last edited by ravenscape; 08-03-2010 at 09:26 PM. Reason: speeling
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Old 08-04-2010, 01:27 AM   #1039476  /  #9
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I think you should all organize a BoF fossiling expedition and camp out on the shore somewhere to party. It's awesome, I could be your Intrepid Guide, take y'all to Joggins and Parrsboro and other hot spots. And cook nutritious breakfasts.
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