Pennsylvanian Footprints in the Black Warrior Basin of Alabama

1
Pennsylvanian Footprints in the Black Warrior
Basin of Alabama

• Ron Buta
• University of Alabama
• and
• Alabama Paleontological Society
• formerly Birmingham Paleontological Society

2
Discovery in Alabama

• Abandoned surface coal mine
• one of many in Walker Co., Alabama
• tetrapod trackways in laminated shale
• discovered by Ashley Allen, Birmingham
  Paleontological Society (BPS)
• quality of tracks very high
• amateur/professional effort to document

3
Types of fossils found

• Temnospondyl amphibian traces (Cincosaurus cobbi)
• limulid trackways and subsurface
  burrows(Kouphichnium)
• millipede traces of unknown ichnospecies
• bivalve traces (Protovirgularia)
• fin traces of gnathosome fish (Undichna)
• numerous insect burrows
• horseshoe crab resting traces (Arborichna)
• allocthonous plant impressions, molds, and casts
• single pair of incomplete wings
  (Paleodictyoptera)
• from N. Pyenson, thesis, Emory University

4
Union Chapel Mine

• 0.3 km2 site in Walker Co., Alabama
• 48 km northwest of Birmingham
• New Acton Coal Company
• Mary Lee seam low sulfur, high grade coal
• many fossiliferous intervals exposed
• fossil lagerstatte (J. Pashin, GSA)

5
(No Transcript)
6
Period of Site

• Late Carboniferous
• Lower Pennsylvanian subdivision
• Langsettian Stage (Westphalian A)
• 310 million years
• laminated fine-grained shales, gray siltstones,
  coal seams

7
(No Transcript)
8
(No Transcript)
9
(No Transcript)
10
Where tracks found

• Spoil piles from mining operation
• rocks with little organic content
• found either exposed on surface, after turning
  over a rock, or splitting a rock
• NO in situ specimens

11
Site Discovery

• Late 1999
• Ashley Allen, member of BPS Oneonta High school
  science teacher

12
(No Transcript)
13
(No Transcript)
14
(No Transcript)
15
(No Transcript)
16
Group Effort

• BPS gets permission to collect fossils from mine
  first field trip January 23, 2000
• site quickly recognized to be significant
• core group of amateurs intensively searches site
  for trackways over next 18 months
• professionals in Tuscaloosa and Atlanta notified

17
(No Transcript)
18
The Track Meets

• June, 2000 BPS decides to hold a series of
  meetings to document the tracks
• Track Meet 1 held at Al. Mus. Nat. Hist.
  Aug. 19, 2000
• Track Meet 2 held at Oneonta H. S. on Oct.
  14, 2000
• Track Meet 3 and Plant Fest held at Anniston
  Mus. Nat. Hist. on May 12, 2001

19
(No Transcript)
20
(No Transcript)
21
(No Transcript)
22
(No Transcript)
23
Site Significance

• By quality, by quantity, and by geologic age,
  it is the most important Carboniferous tracksite
  in the world, H. Haubold, Director, Inst. Of
  Geological Sciences, Martin-Luther-University,
  Germany
• similar assessment made by Jerry MacDonald, who
  discovered a Permian site in New Mexico and
  visited Alabama in April 2000

24
(No Transcript)
25
Alabama during the Coal Age

• Shallow marine shelf covered nw Alabama
• location in tropics south of equator
• Walker Co. was part of Warrior Basin
• mine area was an estuarine tidal mud flat
• very fine mud perfectly preserved tracks and
  activities of animals and some insects

26
(No Transcript)
27
(No Transcript)
28
(No Transcript)
29
Body Fossils? Only one!

• Tracks are the only evidence for the existence of
  most animals who lived in mine area 310 million
  years ago
• NO body fossils of the animals that left the
  tracks have been found
• One invertebrate body fossil found 3-inch
  impressions of two wings of Paleodictyoptera, a
  pre-dragonfly

30
(No Transcript)
31
Stratigraphy

• Pottsville Formation 400m thick
• Mary Lee coal zone spans 30m
• --gtwidespread peat swamp on coastal plain
• vertebrate trackways from interval between Mary
  Lee Newcastle seams
• --gtCincosaurus beds
• J. Pashin (2002)

32
(No Transcript)
33
Vertebrate trace fossil characteristics

• Most vertebrate tracks are undertracks
• Amphibian tracemakers (one ichnospecies)
• bulbous terminations to each digit
• manus 60 size of pes
• elongated 4th digit in pes
• 4 digits manus, 5 digits pes ---gt Cincosaurus
  cobbi
• occasional tail drag or body scrape
• N. Pyenson, thesis, Emory University

34
Manus (hand), Pes (foot)
35
With tail drag
36
(No Transcript)
37
(No Transcript)
38
(No Transcript)
39
(No Transcript)
40
(No Transcript)
41
(No Transcript)
42
Microsaurs

• These small animals are inappropriately termed
  microsaurs, or tiny lizards
• they were not lizards, but amphibians

43
(No Transcript)
44
(No Transcript)
45
Vertebrate Behavioral Characteristics

• wavy tail drags
• body scrapes
• sideways shuffling
• changes in manus pes placement
• abrupt turning motions
• obstacle avoidance
• group movement
• N. Pyenson, thesis, Emory University

46
(No Transcript)
47
(No Transcript)
48
With body scrape?
49
Group movement?
50
Busy scene
51
Predatory trace? Or jump?
52
Large Vertebrate Tracks

• Most tracks found are of small amphibians
• some are quite large
• largest (frogzilla) is 8-10 inches in size
• large animals probably used mudflats as a nursery

53
(No Transcript)
54
(No Transcript)
55
(No Transcript)
56
(No Transcript)
57
(No Transcript)
58
(No Transcript)
59
(No Transcript)
60
(No Transcript)
61
(No Transcript)
62
(No Transcript)
63
Invertebrate Traces

• Mostly due to horseshoe crabs of relatively small
  size
• great variety in their trackways due to
  preservation/exposure differences
• vertebrate/invertebrate specimensequal in numbers

64
(No Transcript)
65
(No Transcript)
66
(No Transcript)
67
(No Transcript)
68
(No Transcript)
69
(No Transcript)
70
(No Transcript)
71
(No Transcript)
72
(No Transcript)
73
(No Transcript)
74
(No Transcript)
75
(No Transcript)
76
(No Transcript)
77
(No Transcript)
78
(No Transcript)
79
Fish Trails and Other Traces
80
(No Transcript)
81
(No Transcript)
82
(No Transcript)
83
(No Transcript)
84
(No Transcript)
85
(No Transcript)
86
(No Transcript)
87
(No Transcript)
88
(No Transcript)
89
(No Transcript)
90
(No Transcript)
91
The effort to preserve the mine

• Halt complete reclamation
• excavate high wall for in situ trackways
• store and display specimens in building on-site
• set up for visitors and school groups

92
(No Transcript)
93
Where to from here?

• Tracks will continue to be researched
• BPS will prepare a monograph illustrating as many
  tracks as possible (see http//bama.ua.edu/rbuta/
  monograph/)
• Hopefully, the era of cooperation between amateur
  and professional paleontologists in Alabama will
  strengthen and continue!

94
Acknowledgements

• The BPS is grateful to New Acton Coal Company for
  permission to collect fossils from the mine
• I also thank Ashley Allen, Steve Minkin, Jim
  Lacefield, Kathy Twieg, Bruce Relihan, Prescott
  Atkinson, Andy Rindsberg, Ed Hooks, David
  Kopaska-Merkel, Tony Martin, Dan Spaulding, and
  Jerry MacDonald for making this presentation
  possible