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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: 10.1080/10420940601006818.

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 Tethys.

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: 10.1080/10420940601010802.

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 palaeocommunities.

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
Science Building
225 South 700 East
St. George, UT  84770   USA
Phone: (435) 652-7758
Fax: (435) 656-4022
E-mail: jharris@dixie.edu
and     dinogami@gmail.com

"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
English Dictionary."
-- D. Graur & W. Martin (_Trends
in Genetics_ 20[2], 2004)