 |
| Fig. 1 Large theropod track from the Early Jurassic. |
It should come as no surprise that
dinosaur tracks are known from thousands of sites across the globe.
After all, an individual dinosaur left hundred of thousands of
footprints throughout its life but had only one skeleton to contribute
to the fossil record. Many dinosaur sites, when discovered, have bone
exposed just as fragments or as a
ghostly cross section visible in a rock outcrop. Such subtle clues are
not easy to see or make sense of. However, footprints are often more
easily recognized. True, footprints
can be distorted and poorly preserved, especially when the animal was
walking on a wet, muddy substrate. But often fossil tracks are easy to
see, even if you are not a paleontologist. Indeed, the late
paleoichnologist W.A.S. Sarjeant surmised that fossil footprints were
probably recognized as being made by animals well before fossil bones
were recognized as the remains of animals (1)
Lida Xing
and his colleagues, and his colleagues Adrienne Mayor, Yu Chen, Jerry
Harris, and Mike Burns, have recently published a very interesting and
enlightening review of Chinese folklore as it relates to dinosaur tracks
and how such myths might help in paleontological prospecting (see link
at ref 2 for free pdf of this paper). The paper focuses on eight
localities scattered across the country. The Chinese written record of
‘dragon bones”, (i.e. fossil bone, most often of mammals) used for
medicinal purposes go back as far as the 3
rd century BC.
However, fossil bone is more transient because it is fragile and easily
destroyed by erosion. Fossil footprints are often less susceptible to
such damage and are often visible in large numbers on extensive surface
exposures. The authors suggest that because of this difference fossil
tracksites can remain exposed for long periods of time and be seen by
many generations of people. Hence it is not surprising that myths would
arise in prescientific cultures to explain these striking features.
 |
| Fig 2 Examples of theropod tracks associated with the various bird legends in China (not to scale). |
These three toed footprints are usually
made by bipedal theropod (carnivorous) dinosaurs. They are strikingly
bird-like in appearance (not unexpected since birds are direct
descendents of small maniraptoran theropods) so it is not surprising
that the myths surrounding them attribute them to birds. In China they
go under a variety of names --
“Divine Birds”, “Feng Huang tracks (a giant Phoenix mythological bird),
“Golden Chicken” and “Heavenly Chicken”. At one locality, the deeply
impressed tracks were thought to have been impressed directly into the
rock, suggesting something supernatural. Today funeral processions
progress along the trackway in the belief that this guides the dead
to heaven. (2)
 |
| Fig 3 Lianhua Baozhai footprint site and rock building on an eroded surface cut into the cliff face. |
The large herbivorous hadrosaur dinosaurs
left three toed tracks but with a different look than the elegant tracks
of theropods. Hadrosaur tracks have thick blunt toes and a broad
rounded heels. At the Lianhua Baozhai site the hadrosaur tracks were
thought to be lotus petals, while fossil mudcracks with the tracks were
interpreted as the veins of lotus leaves. Ripple marks on the rock
surface reinforced a watery environment for these impressions and help
lead to the interpretation of the footprints as lotus plant remains. The
fossil site is located in the middle of a cliff face next to a rock
shelter built in 1256 with an associated Chinese inscription. The lotus
symbolizes purity in many Asian cultures and the translation of “Lianhua
Baozhai” is “The mountain stronghold protected by lotus.” (2, 3)
Fig 4 Lianhua Baozhai.
 |
| Fig 5 Lotus petal shaped hadrosaur tracks on the overhang at Lianhua Baozhai. |
The gigantic sauropod dinosaurs
have a foot structure quite different from that of theropods and, not
surprisingly, leave strikingly different tracks. These dinosaurs are
quadrupedal and the hand and foot impressions are often close together.
Given the great weight of sauropods their tracks can be deep and
somewhat nondescript impressions. In Fushun County a trail of eighteen
sauropod tracks are attributed to an ancient tale of a rhinoceros that
ascended the mountain to get mushrooms. Counting these tracks is thought
to lead to good fortune.(2)
 |
| Fig 6 Sauropod tracks posing as a lucky rhinoceros trackway. |
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However,
fossil footprint folklore is not restricted to China --- there is a
rich tradition from around the world (4). One of the most interesting
comes from the coast of Portugal and involves, again, sauropod
footprints.
 |
| Fig 7 The Church of Nossa Senhora da Mua at the cliff's edge. |
At
Cabo Espichel steeply dipping rocks of Late Jurassic and Early
Cretaceous age rise from the sea to form tall cliffs hundreds of feet
high along the small bay of Lagosterios. On the top of the cliffs is
the Sanctuary of Our Lady of Cape Espichel which dates back to the 15
th
century. Of most interest to our present story is the Memory Heritage
or Church of Nossa Senhora da Mua (Our Lady of the Mule), a small
building located away from the rest the Sanctuary at the very edge of
the
cliff.
 |
| Fig 8. The steeply dipping dinosaur track layers at Cabo Espichel.
Arrow point to location of the small white Church of Nossa Senhora da
Mua perched precariously at the edge of the cliff. |
The
legend underpinning this small building involves two elderly men who
lived in separate cities (Caparica and Alcabideche). Both men, on the
same night, dreamt that the
Virgin Mary appeared on the cliff top astride a giant she-mule. Later,
both men went to the site of their shared dream vision and found a
miraculous image of
Our Lady. Beneath this spot, on the great cliff wall rising out of the
ocean, can be seen lines of large depressions and those closest to the
church were interpreted as the footprints of the Virgin’s giant mule
that she rode out of the ocean and to the top of the cliff. (5)
Inside the Church of Nossa Senhora da Mua is a panel of 18
th
century painted, tin-glazed, ceramic tiles commemorating the appearance
of Our Lady on the mule. The tracks can be clearly seen coming out of
the ocean and up the cliff face. However, we now know that these “mule
tracks” are not miraculous, but are nevertheless interesting, as they
are the footprints of Late Jurassic sauropod dinosaurs. Remarkably, this
panel turns out to be the oldest known illustration of dinosaur tracks!
(6)
 |
| Fig
9 Tile inside Church of Nossa Senhora da Mua showing the Virgin Mary
on a mule and two angels at the top of cliffs at Lagosterios Bay.
Directly behind the mule's back legs you can see the two rows of mule,
er...sauropod, tracks on the steep cliff walls. |
On the cliffs of Lagosterios
forty sauropod trackways occur at eight different levels. The sauropod
tracks, known in the area as far back as the 13
th century, are large and quite visible even from a great distance.
 |
| Fig 10 Stratigraphic column for Cabo Espeichel, showing the positions of the eight sauropod track bearing horizons. |
Although the setting is magnificent, the
height of the exposures and the tilt of the beds making accessing and
studying
the tracks difficult and dangerous. Martin Lockely and his colleagues
used ropes, climbing equipment, and bolts to study and map these sites
in detail in the mid-1990s (7, 8).
One of the track
horizons at Cabo Espichel (level 3) provides evidence of social behavior
in sauropods. Here one can see the footprints of seven subadult
dinosaurs, all about
the same size, traveling close together in the same direction, and
evenly spaced. The details of track morphology clearly show that they
were made by sauropods and not a small herd of celestial mules.
 |
| Figure
11 Map of track level 3 at Cabo Espichel showing the trackways made by
a group of seven juvenile sauropods traveling together. Tracks 8 and 9
are from adults crossing the area earlier. |
 |
| Fig
12. Reconstruction of the juvenile sauropod crossing recorded in level
3 at Cabo Espichel. Note larger adult sauropod trackway already
present as the herd crosses the area. That is trackway 8 in fig 11. |
***********************************
 |
| Fig 13 Edward Hitchcock, the father of the scientific study of dinosaur tracks. |
Although fossil tracks have long been
recognized as tracks of some sort, the serious scientific study of
dinosaur tracks did not begin until the early 19
th century
when Congregationalist Minister and geologist Edwin H. Hitchcock
(1793-1864) began collecting and describing fossil tracks from the Late
Triassic and Early Jurassic rocks of the Connecticut River Valley.
Hitchcock amassed an immense and diverse collection of fossil footprints
that became part of the museum collections at Amherst University and
some of it is still on exhibit today.
 |
| Fig 14 Part of Hitchcock's immense dinosaur track collection as exhibited in the Amherst museum in the 19th century. |
His studies spanned several
decades and resulted in three book-length monographs and numerous
scientific papers (9, 10, 11). Ironically, when Hitchcock began his
studies
dinosaurs were not even known to exist. Faced with peculiar tracks, many
of which were three toed, he made careful study of foot structure in
many different terrestrial vertebrates. After making these comparison
Hitchcock reached the conclusion that the tracks were made by (you
guessed it) giant birds! (12) Sadly, he never recognized the dinosaurian
nature of his discoveries.
For a really great series
of photos of the Hitchcock tracks in the collections at Amherst take a
moment to visit John McCauley's May 31 2011 post at
http://njtntm.blogspot.com/2011/03/amherst-college-beneski-museum-of.html
Figs 2 (modified), 3, 6: Xing et al (ref 2)
Figs 4, 5: http://english.cntv.cn/program/cultureexpress/20111027/103571.shtml
Fig 7: http://pt.wikipedia.org/wiki/Ermida_da_Mem%C3%B3ria_%28Sesimbra%29
Fig 8: http://portugalfotografiaaerea.blogspot.com/2011/02/baia-dos-lagosteiros.html
Fig 9: Antuns and Mateus (ref 6)
Fig 10, 11, 12: Lockley et al (ref 7)
Fig 13: http://en.wikipedia.org/wiki/Edward_Hitchcock
Fig 14: http://oficina.cienciaviva.pt/~pw011/jazidas/icnotaxa_teropodes_triassicofinal_jurassicoinicial.html
References
(1) Sarjeant, W.A.S. 1997. The Earliest Discoveries. in: Farlow, J.O. and Brett-Surman, M.K. (eds.) The Complete Dinosaur. Indiana Univeristy Press: 3-5.
(2) Xing, L., Mayor, A., Chen, Y. and Harris, J.D. 2011. The folklore of dinosaur trackways in China: impact on paleontology. Ichnos
18:213-220. (copy freely available for download at: http://www.xinglida.net/paper_list.htm)
(3) Xing,L., Mayor, A., and Chen, Y. 2011.
Lianhua Baozhai (Lotus Mountain Fortress, Qijiang County of Chongqing
City): Direct evidence of co-existing ancient Chinese and dinosaur
tracks. Geological Bulletin of China. 30(10): 1530-1537 (copy freely available for download at: http://www.xinglida.net/paper_list.htm)
(4) Mayor, A. and Sarjeant, W.A.S. 2001. The folklore of footprints in stone: from Classical Antiquity to the Present. Ichnos 82: 143-163.
(5) Antunes, M.T. 1976. Dinosauros eocretacicos de Lagosteieros. Lisboa: Universidad de Lisboa.
(6) Antunes M.T. and Mateus, O. 2003. Dinosaurs of Portugal. Comptes Rendus PaleoVol 2: 77-95 (copy freely available
for download at http://www.miketaylor.org.uk/tmp/luso.pdf)
(7) Lockley, M.G., Meyer, C.A., and Santos, V.F.d. 1994. Trackway evidence for a herd of juvenile sauropods from the Late Jurassic of Portugal. Gaia 10: 27-25.
(8) Lockley, M. and Meyer, C. 2000. Dinosaur Tracks and Other Fossil Footprints of Europe. Columbia University Press, N.Y.: 323 pages.
(9) Hitchcock, E. 1848. An attempt to discriminate and describe the
animals that made the fossil footmarks of the United States, and
especially of New England. American
Academy of Arts & Sciences Memoir (n.s.) 3:129-256.
(10) Hitchcock, E. 1858. Ichnology of New England: A Report on the Sandstone of the Connecticut Valley, especially its Fossil Footmarks. Commonwealth of Massachusetts: 220 pp.
(11) Hitchcock, E. 1865. Supplement to the Ichnology of New England. Commonwealth of Massachusetts: 96 pp. (copy freely available for download at http://www.ldeo.columbia.edu/~polsen/nbcp/EH1865download.html)
(12) Pick, N. and Ward, F. 2006. Curious Footprints: Professor Hitchcock's Dinosaur Tracks and Other Natural History Treasures at Amherst College. Amherst College Press:121 pages