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Still More New Papers
People keep this up, and I'm gonna need more filing cabinets...!
First, this paper from a book I didn't know existed 'til I got the paper,
and I'm working on finding a copy of the book:
Unwin, D.M., Lü, J., and Deeming, D.C. 2006. Were all pterosaurs
ovirparous?; pp. 141-167 in Lü, J., Kobayashi, Y., Huang, D., and Lee, Y.-N.
(eds.), Papers from the 2005 Heyuan International Dinosaur Symposium.
Geological Publishing House, Beijing.
Then, a bunch from the newest ish of _Ichnos_ -- in a bizarre reversal of
the usual trend, this one is dated in print as 2007, but is actually 2006
since it's out NOW:
Lucas, S.G. 2006. Tetrapod footprint biostratigraphy and biochronology.
Ichnos 14(1-2):5-38. doi: 10.1080/10420940601006792.
ABSTRACT: Tetrapod footprints have a fossil record in rocks of
Devonian-Neogene age. Three principal factors limit their use in
biostratigraphy and biochronology (palichnostratigraphy): invalid ichnotaxa
based on extramorphological variants, slow apparent evolutionary turnover
rates and facies restrictions. The ichnotaxonomy of tetrapod footprints has
generally been oversplit, largely due to a failure to appreciate
extramorphological variation. Thus, many tetrapod footprint ichnogenera and
most ichnospecies are useless phantom taxa that confound biostratigraphic
correlation and biochronological subdivision. Tracks rarely allow
identification of a genus or species known from the body fossil record.
Indeed, almost all tetrapod footprint ichnogenera are equivalent to a family
or a higher taxon (order, superorder, etc.) based on body fossils. This
means that ichnogenera necessarily have much longer temporal ranges and
therefore slower apparent evolutionary turnover rates than do body fossil
genera. Because of this, footprints cannot provide as refined a subdivision
of geological time as do body fossils. The tetrapod footprint record is much
more facies controlled than the tetrapod body fossil record. The relatively
narrow facies window for track preservation, and the fact that tracks are
almost never transported, redeposited or reworked, limits the facies that
can be correlated with any track-based biostratigraphy.
A Devonian-Neogene global biochronology based on tetrapod footprints
generally resolves geologic time about 20 to 50 percent as well as does the
tetrapod body fossil record. The following globally recognizable time
intervals can be based on the track record: (1) Late Devonian; (2)
Mississippian; (3) Early-Middle Pennsylvanian; (4) Late Pennsylvanian; (5)
Early Permian; (6) Late Permian; (7) Early-Middle Triassic; (8) late Middle
Triassic; (9) Late Triassic; (10) Early Jurassic; (11) Middle-Late Jurassic;
(12) Early Cretaceous; (13) Late Cretaceous; (14) Paleogene; (15) Neogene.
Tetrapod footprints are most valuable in establishing biostratigraphic datum
points, and this is their primary value to understanding the stratigraphic
(temporal) dimension of tetrapod evolution.
Lockley, M.G. 2006. A tale of two ichnologies: the different goals and
potentials of invertebrate and vertebrate (tetrapod) ichnotaxonomy and how
they relate to ichnofacies analysis. Ichnos 14(1-2):39-57. doi:
ABSTRACT: Invertebrate and vertebrate (tetrapod) ichnology have evolved as
separate disciplines, largely due to differences in the morphology and
behavior of the tracemakers and the practical impossibility of treating them
as uniform subjects of analysis. Thus, invertebrate ichnotaxa reflect
behavior to a much greater degree than they reflect tracemaker morphology.
The situation is essentially reversed in the case of vertebrates, where
morphology, especially of the foot, plays an important primary role in
ichnotaxonomy (and a secondary role in trackmaker identification), whereas
behavior is of much lesser importance and in many cases can compromise
consistent and effective ichnotaxonomy. Inherent differences in
morphological and behavioral complexity also have significant implications
for our concept of the different potentials of vertebrate and invertebrate
ichnotaxonomy and ichnofacies analysis-as shown in distinctions made between
biotaxonichnofacies and ethoichnofacies, respectively.
Vertebrate tracks not only inform us about morphology, but in the most
general sense also have made huge contributions to our understanding of
vertebrate behavior that have only limited supra-morphological relevance to
ichnotaxonomy or ichnofacies analysis. These contributions have done much to
settle and/or stimulate debate about the posture, speed, abundance,
spatio-temporal distributions and social behavior of dinosaurs, pterosaurs,
birds and other vertebrates, and so have had a dynamic impact on thinking in
the field of vertebrate paleontology and even biostratigraphy. Nonetheless,
this influence may affect ichnotaxonomy as in the case of trackway evidence
of posture that proved important in differentiating the wide- and
narrow-gauge trackways Brontopodus and Parabrontopodus. By contrast, the
impact of invertebrate ichnology on our understanding of invertebrate
behavior is complexly interwoven with an ichnotaxonomy that has a much less
obvious relationship to tracemaker morphology. Thus, the use of invertebrate
traces to decipher the evolution of fossil behavior has proved an ambiguous
and subtle pursuit that does not readily demonstrate parallels with the
evolution of easily identified taxonomic groups.
Because vertebrates (especially tetrapods) are inherently complex
organisms, in comparisons with invertebrates, their traces play a less
ambiguous and more significant role in helping us understand major phases in
vertebrate evolution. In many cases they have pointed to interpretations of
vertebrate paleobiology that were not confirmed by other lines of evidence
until generations later (e.g., polar dinosaur migrations). When vertebrate
tracks are used for palichnostratigraphy or as evidence to support faunal
turnover and extinction events, ichnotaxonomy assumes a significant role in
applied biostratigraphy. Such biostratigraphic utility is far more ambiguous
and much less significant in the case of invertebrate ichnology.
Despite these inherent differences, in the field of ichnofacies
analysis, invertebrate and vertebrate ichnology come together as integrated
components of facies analysis, and potentially have great synergistic
utility in paleoecological and paleoenvironmental analysis. Nevertheless
vertebrate (tetrapod) ichnofacies nomenclature, and terrestrial ichnofacies
analysis in general, is not yet well-established and is currently generating
disparate schools of thought. It is argued that tetrapod ichnofacies are
inherently more diverse and differentiated than invertebrate ichnofacies.
Nicosia, U., Petti, F.M., Perugini, G., D'Orazi Porchetti, S., Sacchi, E.,
Conti, M.A., and Mariotti, N. 2006. Dinosaur tracks as paleogeographic
constraints: new scenarios for the Cretaceous geography of the Periadriatic
region. Ichnos 14(1-2):69-90. doi: 10.1080/10420940601006859.
ABSTRACT: A really unexpected finding of sauropod and theropod footprints in
southern Latium raises to four the number of the trampled levels recognized
in central and southern Italy. After the recent findings in Latest Jurassic
and Early, mid and Late Cretaceous carbonate platform deposits of the
Periadriatic region, dinosaur footprints seem to provide very important
paleogeographic constraints for reconstructing the geodynamic history of the
Mediterranean area. The presence of a varied ichnoassociation makes
acceptance of the current paleogeographic models concerning the relative and
absolute position of the Laziale-Abruzzese-Campano and of Apulian-Dinaric
domains during the Late Cretaceous more and more problematic. Dinosaur
footprints, combined with other paleontological data, demonstrate that these
areas were never completely pulled apart by deep seaways, while frequent or
continuous links between them, and to southern and northern mainlands,
probably persisted. These data also allowed us to improve our understanding
of the timing of the Mesozoic plate motion in this segment of the Western
Hunt, A.P., and Lucas, S.G. 2006. Tetrapod ichnofacies: a new paradigm.
Ichnos 14(1-2):59-68. doi: 10.1080/10420940601006826.
ABSTRACT: We recognize three fundamental terms in ichnology: (1)
ichnoassemblage, which is an assemblage of ichnofossils conceptually
equivalent to an assemblage of body fossils; (2) ichnocoenosis, which is a
trace fossil assemblage produced by a biological community that can be
characterized by morphological criteria; and (3) ichnofacies, which refers
to recurrent ichnocoenoses that represent a significant portion of
Phanerozoic time. There are two different kinds of ichnofacies,
ethoichnofacies (mostly invertebrate ichnofacies) and biotaxonichnofacies
(mostly tetrapod ichnofacies). Nonmarine invertebrate ichnologists now
recognize five archetypal ichnofacies (Mermia, Skolithos, Scoyenia,
Coprinisphaera, Psilonichnus) to which we add the Octopodichnus ichnofacies.
We propose a coherent and consistent classification and nomenclature for
tetrapod ichnofacies. We name five archetypal vertebrate ichnofacies for
nonmarine environments: Chelichnus, Grallator, Brontopodus, Batrachichnus
and Characichnos ichnofacies.
Valdiserri, D., and Avanzini, M. 2006. A tetrapod ichnoassociation from the
Middle Triassic (Anisian, Pelsonian) of northern Italy. Ichnos
14(1-2):105-116. doi: 10.1080/10420940601010703.
ABSTRACT: A new Middle Triassic ichnofauna recovered nearby the town of
Tisens (Bozen) in the Adige Valley (Trentino, Northern Italy) is described.
A relatively large ichnoassociation, in which various ichnogenera can be
recognized, comes from the basal inter-supratidal layers of a mixed
carbonate siliciclastic unit of Pelsonian (Middle Anisian) age. Most of the
isolated footprints and trackways pertain to lizard-like reptiles referable
to Rhyncosauroides and, subordinately, to archosaurian reptiles. In
particular, the ichnogenera Rotodactylus, Synaptichnium and Chirotherium
have been recognized. Many tracks are at present unidentified; among them a
lizard-like morphotype (morphotype A). The site also yelded numerous fossil
plant horizons and some scattered vertebrate remains referable to
Placodontidae (cf. Placodus gigas). The site shows the continuity in the
Pelsonian of the "chirothere ichnofauna" and the dominance of
Rhynchosauroides in carbonate, tidal flat environments.
Whyte, M.A., Romano, M., and Elvidge, D.J. 2006. Reconstruction of Middle
Jurassic dinosaur-dominated communities from the vertebrate ichnofauna of
the Cleveland basin of Yorkshire, UK. Ichnos 14(1-2):117-129. doi:
ABSTRACT: Globally, skeletal remains of dinosaurs are particularly rare
throughout much of the Middle Jurassic. Thus, other sources of evidence, and
most importantly ichnofaunas, are important indicators of the contemporary
terrestrial vertebrate communities. The outcrops of the Ravenscar Group
(Aalenian-Bajocian) within the Cleveland Basin of Yorkshire, UK, which have
recently been recognised as a megatracksite of global significance, provide
one such major source of ichnofaunal information of this age. A
comprehensive database on the variety and occurrence of dinosaur and other
vertebrate traces within the Ravenscar Group has been built from a long-term
and detailed study of the sequence. Thirty different and distinct
morphotypes of vertebrate traces have been recognised and are being analysed
and further differentiated morphometrically. Some of the morphotypes
represent behavioural, preservational and perhaps ontogenetic variants of
other morphotypes, but nevertheless the range of quadrupedal and bipedal
prints allows an overall fauna of sauropod, stegosaurian, ornithopod and
theropod dinosaurs along with crocodiles, pond turtles and fish to be
reconstructed. The distribution and abundance of prints and print types
within the succession shows evidence of environmental control on the
behaviour and distribution of the vertebrates. Case studies highlight both
the advantages and disadvantages of this type of data in reconstructing
Lockley, M., Mitchell, L., and Odier, G.P. 2006. Small theropod track
assemblages from Middle Jurassic eolianites of eastern Utah: paleoecological
insights from dune ichnofacies in a transgressive sequence. Ichnos
14(1-2):131-142. doi: 10.1080/10420940601010901.
ABSTRACT: New discoveries show that very small theropod tracks (cf.
Wildeichnus) are abundant in the upper part of the Moab Member, recently
assigned to the Curtis Formation (formerly considered part of the Entrada
Formation) in the Mid-?Late Jurassic of eastern Utah. The tracks represent a
distinct small-theropod ichnofacies associated with eolian dune deposits
that is easily differentiated from the water-lain beds of the overlying
Megalosauripus-Therangospodus ichnofacies, which comprises the
single-surface Moab megatracksite. Pterosaur track assemblages, representing
the Pteriachnus ichnofacies, are found a few meters above the megatracksite
surface in the upper tongue of the Summerville Formation.
The small theropod ichnofacies is reminiscent of other early Mesozoic
dune facies ichnofaunas from the Wingate and Navajo formations (Late
Triassic and Early Jurassic) where small theropod tracks occur in
association with other small tetrapod footprints. All such examples
evidently represent a recurrent dune facies ecosystem dominated by
diminutive vertebrates. Because the small theropod ichnofacies is one of
three ichnofacies found in a thin stratigraphic sequence (<20 m) that
contains no body fossils, it is clear that vertebrate tracks play an
important role in providing insight into the paleoecology of units
previously considered devoid of any useful fossil evidence. The three
successive ichnofacies represent a transgressive transition from sand dunes,
through sandy shoreline to shallow marine environments, each with its quite
distinct vertebrate fauna.
Avanzini, M., García-Ramos, J.C., Lires, J., Piñuela, L., and Lockley, M.G.
2006. Crocodylomorph tracks from the Late Jurassic of Asturias (Spain).
Ichnos 14(1-2):143-153. doi: 10.1080/10420940601010943.
ABSTRACT: Some small and medium-sized crocodylomorph footprints are
described from the Late Jurassic (Kimmeridgian) coastal and deltaic units of
the northern Spain (Asturias). There are at least four footprint
morphotypes. Three of them, with well preserved trackways, are included in
the ichnogenus Crocodylopodus (Crocodylopodus isp. and Crocodylopodus
meijidei); the fourth one, documented by some isolated large footprints, is
referable to the ichnogenus Hatcherichnus. This ichnoassociation confirms
the presence of small crocodilians in palaeoenvironments apparently
dominated by dinosaurs. The presence of Hatcherichnus seems to confirm the
affinity between the Iberian and North American ichnofaunas.
Jerry D. Harris
Director of Paleontology
Dixie State College
225 South 700 East
St. George, UT 84770 USA
Phone: (435) 652-7758
Fax: (435) 656-4022
"Trying to estimate the divergence times
of fungal, algal or prokaryotic groups on
the basis of a partial reptilian fossil and
protein sequences from mice and humans
is like trying to decipher Demotic Egyptian with
the help of an odometer and the Oxford
-- D. Graur & W. Martin (_Trends
in Genetics_ 20, 2004)