Carboniferous human bones -- an evaluation
This document evaluates some of the claims of
"human bones in Carboniferous-age rocks" in eastern Pennsylvania, as
presented by Ted Holden (
) and initially discovered
and interpreted by Ed Conrad (
). Ted and Ed have
graciously provided specimens of their material for analysis, and the results
are presented here. My thanks to them for making this possible.
Ed and Ted's claims
You can read the details of the claims being made for these fossils at:
"human bones in Carboniferous-age rocks". Basically, they can be
summarized as three key claims:
- The specimens consist of fossil bone
- The fossil bone is not from an expected Carboniferous animal, it is
- The specimens occur in situ in Carboniferous bedrock
By examining specimens, only the first two claims can be tested. Even if
the specimens are fossil bone (#1), and are human (#2), Ted and Ed would
still have to fully document the geologic context for these specimens
(#3) before their claims would be fully substantiated. The importance
of this can not be overemphasized -- fossil human bone without
unambiguous, detailed, irrefutable documentation of the collection
point of the same specimen (not just any specimen) is an
absolute requirement. Without this, the isolated specimens are
worthless for demonstrating the case even if they
are fossil human bone.
Ted makes additional claims, but they implicitly depend upon the
validity of the ones stated above.
The rocks in the Shenandoah area are part of the Appalachian mountain
belt and have been extensively folded and faulted. Most of the deformation
is dominated by anticlines and synclines (like the crests and troughs of
waves, respectively) with axes roughly parallel the Atlantic coast, and
large thrust (reverse) faults with similar surface orientation. Smaller
normal faults also occur at other orientations. Shenandoah
occurs within a roughly east-west-oriented syncline, known
as the "Western Middle Anthracite Field" containing
Late Carboniferous (Pennsylvanian) age rocks, mainly of the
Pottsville Group (Pp) and overlying Llewellyn Formation (Pl). The
syncline is surrounded by older
Early Carboniferous (Mississippian) age rocks of the Mauch Chunk
Formation (may have been raised to "Group" status).
Many of these units contain river-deposited shales, siltstones,
sandstones, conglomerates, coal, and paleosols (fossil soils).
Plant fossils are common as impressions and casts, particularly in
association with the coal seams. Apparently there are even
upright tree trunks in the Llewellyn Formation (p.38 of Wood
et al., 1986).
Due to the uplift related to the mountain-building, the coal
of this area was heated to high temperatures and experieced high pressures
that converted it to anthracite, the highest grade of coal. Mining occured
mainly in the Llewellyn Formation, both in underground and surface (strip)
mining operations that have substantially altered the surface of the area.
A good summary of the geology of the region can be found in Wood et al.,
1986, and see also Paul Heinrich's summary below, which has references to
more detailed information.
excerpt from the Geologic Map of Pennsylvania, 1980, compiled
by Berg et al.
Key (quoted from Berg et al., 1980):
Detailed discussion of local geology
by Paul Heinrich,
- PENNSYLVANIAN (LATE CARBONIFEROUS)
- Pl -- Llewellyn Formation: "Gray, fine- to coarse-grained sandstone,
siltstone, shale, conglomerate, and numerous anthracite coals in
- Pp -- Pottsville Group (Anthracite region):
"Gray conglomerate, fine- to coarse-grained
sandstone, and siltstone and shale containing minable anthracite coals.
Includes three formations, in descending order: Sharp Mountain -- conglomerate
and conglomeratic sandstone; Schuylkill -- sandstone and conglomeratic
sandstone; Tumbling Run -- conglomeratic sandstone and sandstone."
- MISSISSIPIAN (EARLY CARBONIFEROUS)
- Mmc -- Mauch Chunk Formation: "Greyish-red shale, siltstone,
sandstone, and some conglomerate; some local non-red zones. Includes
Loyalhanna Member (crossbedded, sandy limestone) at bas in south-central
and southwestern Pennsylvania; also includes Greenbrier Limestone Member
and Wymps Gap and Deer Valley Limestones, which are tongues of the Greenbrier.
Along Allegheny Front from Blair County to Sullivan County, Loyalhanna Member
is greenish-gray, calcareous, crossbedded sandstone.
What to expect in the Carboniferous
During the Carboniferous, land areas with enough
water supply were covered with vegetation dominated
by sphenopsids ("giant horsetails"), giant lycopod trees, both spore
and seed tree ferns, and a few types of early conifer. The sphenopsids
and giant lycopods were particularly common, and were responsible for
much of the coal formed during this period. Often the upright stumps
and roots of these plants are preserved in directly in association with
the coal and other fossil remains. Because of their pithy core, these plants
commonly occur as sandstone-infilled casts which were produced when the
core of the plant rotted out, and a cavity was left. For details of
the anatomy of the plants of the Carboniferous, see Taylor
(1981) and Stewart and Rothwell (1993) in the
Animal life included insects (dragonflies, cockroaches, millepedes,
and others) and other arthropods (e.g., arthropleurids and eurypterids), and a variety of vertebrates. The vertebrate life on land included amphibians
and reptiles. In rivers and lakes, many types of amphibians and fish occured.
The fish included freshwater sharks and large, carnivorous lobe-finned fish.
In terms of size, some of these vertebrates got quite large. For example, the
Carboniferous embolomere amphibian Eogyrinus attained a length of
2 metres (Carroll, 1993, p.175), and ancathodian fish like Acanthodopsis and the gyracanthids (see p.93 to 95 of Long, 1995), and the xenacanthid sharks (see p.75-76 of Long, 1955) reached lengths of 1 to 4 metres. But the
ultimate in vertebrate size in the Carboniferous may have been attained
by the rhizodontiform lobe-finned (crosspterygian) fish. These had heavy
skeletons with armoured skulls and large pointed teeth known as Rhizodus. These animals are estimated to have reached lengths of 6-7
metres (Long, 1993, p.190 talks about a jaw from the Carboniferous of
Scotland that is 1 metre long!), and individual teeth approach 22cm in length.
Smaller examples of Rhizodus teeth are figured below.
Obviously, the mere size of fossil bone material from the Carboniferous is not
enough to establish that something anomalous is present.
Ted has claimed that some of the "tooth" structures found are too
large to plausibly be from any Carboniferous animal. However, both fish
and land vertebrates of the Carboniferous are known to have
relatively large teeth. The teeth of certain lobe-finned fish were
particularly large and are particularly common in Carboniferous sediments
(even I have some specimens from the Carboniferous of Nova Scotia).
For more details, see:
Tusks and spines
Ted has claimed that in the Carboniferous, "fish do not have tusks".
While the vertebrate animals of the Carboniferous did not possess tusks,
there were fish with large dermal spines which are superficially similar, got
quite large, and which could be
confused with tusks.
In summary, there are many types of vertebrate remains known from the
Carboniferous. The detailed morphology of the fossil bone must be used to
distinguish between organisms which are expected from this interval, and
ones that are not. Size is not enough.
Fossil bone is usually recognized on the basis of its microscopic structure,
including the presence of tubular channels -- the haversian canals --
with laminated mineral structure around them. These channels are larger,
and the surrounding laminated structure thinner, towards the centre of
most types of bone, defining the "marrow"; and the bone is denser and
the channels narrower towards the exterior. The tubular channels are typically
aligned along the length of the bone, and often branch and interconnect
with other channels. Even if the channels have
been infilled with minerals (i.e. the specimen is permineralized), the
channels will usually still be recognizable in microscopic cross section.
In exceptionally well-preserved fossil bone, additional structures, including
laminae and canaliculae will be observable, and represent structures
developed around the individual bone cells that were once embedded in the
mineral framework of the bone. By far, bone microstructure is the
most conclusive means by which fossil bone can be identified.
Compositionally, bone is originally
the mineral hydroxyapatite, which is approximately CaPO4, calcium
phosphate (give or take some trace elements and water). Although the
fossil preservation process often replaces the calcium phosphate,
composition can be a secondary indication of fossil bone, particularly
because it is common for the primary calcium phosphate to be preserved,
even if the fossils are from rocks older than Carboniferous. In hand
sample, calcium phosphate from bone is usually black or dark brown and slightly
vitreous in lustre on fresh surfaces, but as it wheathers it often
aquires a dark blue colour and eventually it turns white. Because of
the distinctive colouration (particulaly the blue), it is often easy
to recognize even tiny fragments of bone.
Shape is probably the least diagnostic of characteristics of fossil bone.
However, it can be used if the bone is complete, so the points of
articulation between bones are visible. Often there is a distinct difference
in texture between the articulating and non-articulating surface, and the
articulating surfaces are usually developed into distinctive shapes (e.g.,
ball and socket). It is also sometimes possible to recognize muscle/tendon
scars and the apertures of blood vessels on the surface of the bone.
Identification of fossil bone from shape alone without complete specimens
is unreliable, because many other fossil and non-fossil structures
can correspond to the typical sub-cylindrical shape of a fossil bone.
For comparison purposes, a hand sample with a polished surface and
thin sections of a well-preserved Cretaceous-age dinosaur bone have
been prepared. Although this specimen is not from the Carboniferous, bone
from that period is too valuable to sacrifice for destructive preparation,
and a dinosaur bone shows basically the same microstructural features of
fossil bone found from the Carboniferous. For that matter, land vertebrate
bone is so similar at microscopic scale that it would take an
expert to recognize a difference anyway. For gross structure, it
is effectively identical to what would be expected if fossil bone
is present. If you do not believe me, look up a text on bone histology
of humans. Perhaps surprisingly, you will see very similar
microscopic structures to what is present in this dinosaur bone.
dinosaur bone, Cretaceous, Alberta, Canada.
TH96-001 -- click for details with minimal interpretation, so
you can evaluate the images yourself without being biased by
This specimen was collected by Ted Holden in the area around
Shenandoah, Pennsylvania, apparently from Carboniferous bedrock,
sometime in early 1996.
It was provided to the author for study in early April, 1996. The specimen has
been designated the temporary number TH96-001, and has been prepared
with a polished surface and two thin sections.
TH96-001 -- click for details with my interpretation
EC96-001 -- click for details with minimal interpretation, so
you can evaluate the images yourself without being biased by
This specimen was collected by Ed Conrad from a spill bank in the area of Mahanoy City, a town about 3 miles from Shenandoah, Pennsylvania. It was
collected in 1981. I have not received confirmation, but I believe it is
illustrated at the right of
http://www.access.digex.net/~medved/conrad/bone1.jpg on Ted's WWW page.
The specimen was provided to the author for study in late April, 1996.
It been designated the temporary number EC96-001, and has been cut into
3 pieces (A, B, and C), with polished surfaces on each cut.
EC96-001 -- click for details with my interpretation
Conclusions are hidden here,
so you have a chance to view the specimens before seeing them.
Berg, T.M. (chief compiler) et al., 1980. Geologic Map of
Pennsylvania, 1980. State of Pennsylvania Department of Environmental
Resources. 1:250 000.
Carroll, R.L., 1988. Vertebrate Paleontology and Evolution. W.H. Freeman
and Company: New York, p.1-698. ISBN 0-716-71822-7.
Dawson, John William, 1868. Acadian Geology. The Geological Structure,
Organic Remains, and Mineral Resources of Nova Scotia, New Brunswick,
and Prince Edward Island. Second edition. MacMillan and Co.:London, p.1-694.
Eastman, C.R., (translator and editor) 1932. Text-Book of Palaeontology, by
Karl A. von Zittel. Volume II. MacMillan and Co.:London, p.1-464.
Long, J.A., 1995. The Rise of Fishes. 500 Million Years of Evolution.
Johns Hopkins University Press: Baltimore, p.1-223. ISBN 0-8018-4992-6.
Stewart, W.N. and Rothwell, G.W., 1993. Paleobotany and the Evolution
of Plants, Second Edition. Cambridge University Press: Cambridge, p.1-521.
Taylor, T.N., 1981. Paleobotany. An Introduction to Fossil Plant Biology.
McGraw-Hill Book Company: New York, p.1-589. ISBN 0-07-062954-4.
Wood, G.H., Jr.; Kehn, T.M.; and Eggleston, J.R., 1986. Depositional
and structural history of the Pennsylvania Anthracite region. Geological
Society of America, Special Paper 210, p.31-47.
Zittel, Karl A., 1887-1890. Handbuch der Palaeontologie.
Abteilung I. Palaeozoologie. Band III.
Vertebrata (Pisces, Amphibia, Reptilia, Aves). Druck Und Verlag Von R.
Oldenburg: München und Leipzig, p.1-900.
First released, May 22, 1996.
Opinions expressed here are those of the author unless otherwise indicated.
Please ask for permission prior to using this material in a form other than
a WWW link.