Cretaceous Vertebrate Research Articles

Vertebrate fauna of the late Campanian (Judithian) Fort Crittenden Formation, and the age of Cretaceous vertebrate faunas of southeastern Arizona (U.S.A.)

Vertebrate fauna of the late Campanian (Judithian) Fort Crittenden Formation, and the age of Cretaceous vertebrate faunas of southeastern Arizona (U.S.A.)

New Cuvieronius finds from the Pleistocene of central Mexico

In the southern part of the State of Puebla, central Mexico, the town of Tepexi de Rodriguez is a well-known fossiliferous area because of the beautiful and extraordinary Early Cretaceous vertebrates recovered from the Tlayua Quarry (Applegate, 1996; Espinosa-Arrubarrena and Applegate, 1996; Reynoso-Rosales, 1996a, 1996b, 1997, among others), and a Tertiary plant locality known as “Los Ahuehuetes” (Magallón-Puebla and Cevallos-Ferriz, 1994; Velasco de León and Cevallos-Ferriz, 1997; Ramírez-Garduño, 1998, among others). The Axamilpa river drains this area and along its banks a sequence of Late Cenozoic sands, silts, and gravels are exposed. In these sediments scattered fossil mammalian remains had been recovered (Torres-Martínez and Agenbroad, 1991; Montellano-Ballesteros and Castro-Azuara, 1996; Fig. 1).

NEW CUVIERONIUS FINDS FROM THE PLEISTOCENE OF CENTRAL MEXICO

In the southern part of the State of Puebla, central Mexico, the town of Tepexi de Rodriguez is a well-known fossiliferous area because of the beautiful and extraordinary Early Cretaceous vertebrates recovered from the Tlayua Quarry (Applegate, 1996; Espinosa-Arrubarrena and Applegate, 1996; Reynoso-Rosales, 1996a, 1996b, 1997, among others), and a Tertiary plant locality known as “Los Ahuehuetes” (Magallón-Puebla and Cevallos-Ferriz, 1994; Velasco de León and Cevallos-Ferriz, 1997; Ramírez-Garduño, 1998, among others). The Axamilpa river drains this area and along its banks a sequence of Late Cenozoic sands, silts, and gravels are exposed. In these sediments scattered fossil mammalian remains had been recovered (Torres-Martínez and Agenbroad, 1991; Montellano-Ballesteros and Castro-Azuara, 1996; Fig. 1).

OKADA, H. & MATEER, N. J. (eds) 2000. Cretaceous Environments of Asia. Developments in Palaeontology and Stratigraphy Series, Volume 17. vii + 255 pp. Amsterdam, Lausanne, New York, Oxford, Shannon, Singapore, Tokyo: Elsevier, Price Nlg 295.00, Euro 133.87, US $154.50 (hard covers). ISBN 0 444 50276 9.

From my rather limited perspective as a vertebrate palaeontologist (albeit one that is informed by some of my current work on the Cretaceous vertebrates of Asia), any prospect of being able to improve my understanding of the general regional geology and stratigraphy of ‘Central Asia’ (particularly Mongolia and northern China) is to be welcomed. This whole area has a distinctly ‘will-o-the-wisp’ quality particularly when it comes to stratigraphic correlation. Much (dare I say the majority?) of the published information appears to rely upon heavily circular argument. Therefore the prospect of learning a little more about the stratigraphy, general geology and …

Palynologically calibrated vertebrate record from North Dakota consistent with abrupt dinosaur extinction at the Cretaceous-Tertiary boundary

Research Article| January 01, 2001 Palynologically calibrated vertebrate record from North Dakota consistent with abrupt dinosaur extinction at the Cretaceous-Tertiary boundary Dean A. Pearson; Dean A. Pearson 1Pioneer Trails Regional Museum, Bowman, North Dakota 58623, USA Search for other works by this author on: GSW Google Scholar Terry Schaefer; Terry Schaefer 1Pioneer Trails Regional Museum, Bowman, North Dakota 58623, USA Search for other works by this author on: GSW Google Scholar Kirk R. Johnson; Kirk R. Johnson 2Denver Museum of Nature and Science, Denver, Colorado 80205, USA Search for other works by this author on: GSW Google Scholar Douglas J. Nichols Douglas J. Nichols 3U.S. Geological Survey, MS 939, Box 25046, Denver, Colorado 80225, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Dean A. Pearson 1Pioneer Trails Regional Museum, Bowman, North Dakota 58623, USA Terry Schaefer 1Pioneer Trails Regional Museum, Bowman, North Dakota 58623, USA Kirk R. Johnson 2Denver Museum of Nature and Science, Denver, Colorado 80205, USA Douglas J. Nichols 3U.S. Geological Survey, MS 939, Box 25046, Denver, Colorado 80225, USA Publisher: Geological Society of America Received: 16 Jun 2000 Revision Received: 26 Sep 2000 Accepted: 03 Oct 2000 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2001) 29 (1): 39–42. https://doi.org/10.1130/0091-7613(2001)029<0039:PCVRFN>2.0.CO;2 Article history Received: 16 Jun 2000 Revision Received: 26 Sep 2000 Accepted: 03 Oct 2000 First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Dean A. Pearson, Terry Schaefer, Kirk R. Johnson, Douglas J. Nichols; Palynologically calibrated vertebrate record from North Dakota consistent with abrupt dinosaur extinction at the Cretaceous-Tertiary boundary. Geology 2001;; 29 (1): 39–42. doi: https://doi.org/10.1130/0091-7613(2001)029<0039:PCVRFN>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract New data from 17 Cretaceous-Tertiary (K-T) boundary sections and 53 vertebrate sites in the Hell Creek and Fort Union Formations in southwestern North Dakota document a 1.76 m barren interval between the highest Cretaceous vertebrate fossils and the palynologically recognized K-T boundary. The boundary is above the formational contact at 15 localities and coincident with it at two, demonstrating that the formational contact is diachronous. Dinosaurs are common in the highest Cretaceous vertebrate samples and a partial dinosaur skeleton in the Fort Union Formation is the highest recorded Cretaceous vertebrate fossil in this area. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

A eutherian mammal from the Early Cretaceous of Russia and biostratigraphy of the Asian Early Cretaceous vertebrate assemblages

Prokennalestes abramovi n.sp. is described based on M2 from the upper Barremian-middle Aptian (Early Cretaceous) Mogoito locality in Transbaikalia, Russia. It differs from the Mongolian species of Prokennalestes (Khoboor, early Albian) by a combination of one primitive character (steeper and shorter lingual slopes of the paracone and metacone), one more derived character (larger size), and some characters of uncertain polarity (small preparastyle, lack of labial cuspules along the ectoflexus). P. abramovi n.sp. is the oldest eutherian mammal so far described, and its discovery extends the known geological range of Eutheria by 10–15 Ma. The Tsagantsabian land-vertebrate biochron can be defined by a dominance of sinemyid turtles; the Khukhtekian by a dominance of macrobaenids.

Evidence for extreme climatic warmth from late cretaceous arctic vertebrates

A Late Cretaceous (92 to 86 million years ago) vertebrate assemblage from the high Canadian Arctic (Axel Heiberg Island) implies that polar climates were warm (mean annual temperature exceeding 14 degreesC) rather than near freezing. The assemblage includes large (2.4 meters long) champsosaurs, which are extinct crocodilelike reptiles. Magmatism at six large igneous provinces at this time suggests that volcanic carbon dioxide emissions helped cause the global warmth.

Ancient Sharks and Rays

The item “Shark and ray extinctions” by Ann Simon Moffat (Research News, 31 Oct., [p. 801][1]) featured a discussion on a portion of our work on Late Cretaceous (Maastrichtian) vertebrates found in the Fox Hills Formation and Paleocene Cannonball Formation of North Dakota, as reported at the recent Society of Vertebrate Paleontology meeting ([1][2]). Moffat discussed the Cretaceous-Tertiary (K-T) boundary extinctions as demonstrated by cartilaginous fish faunas of the Western Interior Seaway, and we would like to clarify some aspects of our research that she mentioned. We have studied more than 40 sites in the Fox Hills Formation and 70 sites in the Cannonball Formation. There is little disagreement that the 22 species of sharks and rays we found in the Fox Hills were extinct by the Paleocene; rather, the issue may be the rapidity of that extinction. As suggested by the comments attributed to J. David Archibald, the K-T boundary section is not complete because units of terrestrial Hell Creek and Ludlow Formations intervene in North Dakota, where we are working. The K-T boundary occurs within this interval of regression ([2][3]), making precise correlation between the marine cartilaginous fish faunas and the terrestrial vertebrate faunas difficult. These facies, although complex, are well understood paleoenvironmentally. Similar depositional conditions created both the Fox Hills and Cannonball Formations. There is little likelihood the faunal changes we document resulted from environmental changes, as suggested by Archibald, for we have sampled similar suites of nearshore marine facies on each side of the K-T boundary. Habitat-sensitive molluscan faunas confirm similar origins of most Fox Hills and Cannonball facies ([3][4]). Furthermore, given the similarity of habitats sampled, there is little likelihood that our data result from habitat displacement rather than biological extinction. Significant species-level change in cartilaginous fish faunas occurred across the K-T boundary in the Williston Basin, and apparently globally, at a rate not yet determined. 1. [↵][5]1. J. W. Hoganson, 2. J. M. Erickson, 3. A. M. Cvancara, 4. F. D. Holland Jr. , J. Vertebr. Paleontol. 17, 53 (1997). [OpenUrl][6] 2. [↵][7]1. E. C. Murphy, 2. D. J. Nichols, 3. J. W. Hoganson, 4. N. F. Forsman , N.D. Geol. Survey Rept. Invest. 98, 1 (1995). [OpenUrl][8] 3. [↵][9]1. A. M. Cvancara , Contrib. Mus. Paleontol. Univ. Mich. 20, 1 (1966); [OpenUrl][10] 1. I. Speden , Yale Peabody Mus. Bull. 33, 1 (1970); [OpenUrl][11] 1. J. M. Erickson , Bull. Am. Paleontol. 284, 131 (1974). [OpenUrl][12] [1]: /lookup/doi/10.1126/science.278.5339.801 [2]: #ref-1 [3]: #ref-2 [4]: #ref-3 [5]: #xref-ref-1-1 View reference 1 in text [6]: {openurl}?query=rft.jtitle%253DJ.%2BVertebr.%2BPaleontol.%26rft.volume%253D17%26rft.spage%253D53%26rft.atitle%253DJ%2BVERTEBR%2BPALEONTOL%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [7]: #xref-ref-2-1 View reference 2 in text [8]: {openurl}?query=rft.jtitle%253DN.D.%2BGeol.%2BSurvey%2BRept.%2BInvest.%26rft.volume%253D98%26rft.spage%253D1%26rft.atitle%253DND%2BGEOL%2BSURVEY%2BREPT%2BINVEST%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [9]: #xref-ref-3-1 View reference 3 in text [10]: {openurl}?query=rft.jtitle%253DContrib.%2BMus.%2BPaleontol.%2BUniv.%2BMich.%26rft.volume%253D20%26rft.spage%253D1%26rft.atitle%253DCONTRIB%2BMUS%2BPALEONTOL%2BUNIV%2BMICH%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [11]: {openurl}?query=rft.jtitle%253DYale%2BPeabody%2BMus.%2BBull.%26rft.volume%253D33%26rft.spage%253D1%26rft.atitle%253DYALE%2BPEABODY%2BMUS%2BBULL%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [12]: {openurl}?query=rft.jtitle%253DBull.%2BAm.%2BPaleontol.%26rft.volume%253D284%26rft.spage%253D131%26rft.atitle%253DBULL%2BAM%2BPALEONTOL%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx

Cosmopolitanism among Gondwanan Late Cretaceous mammals

Consistent with geophysical evidence for the breaking up of Pangaea, it has been hypothesized that Cretaceous vertebrates on progressively isolated landmasses exhibit generally increasing levels of provincialism1,2,3, with distinctly heightened endemism occurring at the beginning of the Late Cretaceous4. The Cretaceous fossil record from the southern supercontinent of Gondwana has been much too poor to test this hypothesis with regards to mammals (Fig. 1 ). Early Cretaceous mammals are known only from isolated sites in Argentina5, Australia6,7, Cameroon8,9 and Morocco10. Apart from several occurrences in South America11, knowledge of Late Cretaceous Gondwanan mammals is limited to a single site in India that previously yielded a few specimens of placental mammals12,13, and a site in Madagascar that previously yielded only one indeterminate tooth fragment14. Here we report the occurrence of a highly specialized and distinctive group of extinct mammals, the Sudamericidae (Gondwanatheria), in the Late Cretaceous of Madagascar and India. These new records comprise the first evidence of gondwanatheres outside South America and the first indication of cosmopolitanism among Late Cretaceous Gondwanan mammals. Antarctica may have served as an important Cretaceous biogeographic link between South America and Indo-Madagascar.

Paleoecology of an Estuarine, Incised-Valley Fill in the Dinosaur Park Formation (Judith River Group, Upper Cretaceous) of Southern Alberta, Canada

Although portions of ancient estuarine paleochannels have high theoretical potential for burial and preservation of vertebrate skeletal remains, relatively few fossiliferous examples have been documented. A recently described, mud-filled incised-valley system (herein abbreviated OMFIV) in the Dinosaur Park Formation (late Campanian) of southeastern Alberta is a spectacular example of this potential. So far, this deposit has yielded thousands ofdisarticulated vertebrate fossils from basal and internal lag deposits, and tens of associated to articulated specimens from internal bedding surfaces. The OMFIV formed in the freshwater (upstream) portion of the central zone of low energy in a stretched-out, estuarine setting that extended >200 km up into a plain of very low slope. The high abundance and concentration of fossils is probably an artifact resulting from an absence of a diluting sandy bedload. Combined paleontologic and sedimentologic data indicate that (1) disarticulation and reworking of fossils took place within the OMFIV and (2) the assemblage is largely autochthonous to parautochthonous. The OMFIV vertebrate assemblage is more similar in overall composition to previously described coastal rather than inlandpaleocommunities of the Judith River Group. However, the OMFIV assemblage differs from coastal assemblages in that: (1) it is overwhelmingly aquatic compared to assemblages from other Dinosaur Park Formation paleochannel deposits; (2) the taxa Hybodus, Atractosteus, Belonostomus, and Paralbula dominate the vertebrate assemblage; (3) teleost fish are very abundant; (4) it includes taxa generally considered more typical of marine settings (ratfish, elasmosaurs, ?Lophochelys, and ?Baptornis); and (5) although terrestrial vertebrates are rare, ceratopsians and marsupials are present in unusual abundance, indicating that these taxa were common in paleoenvironments adjacent to the OMFIV On the basis of sedimentologic and paleontologic data, we conclude that: (1) the OMFIVfossil assemblage represents a distinct subset of the nonmarine Judithian coastalpaleocommunity comprising a number of taxa adapted to the freshwater portion of the central zone of low energy in an estuarine setting; (2) among Cretaceous vertebrates, teleost fish are sensitive paleoenvironmental indicators; and (3) because of high preservational potential, estuarine facies are important potential sources ofpaleoecological data.

Late Cretaceous non-marine vertebrates from southern France: A review of recent finds

During the last few years, systematic prospections and excavations in the non-marine Campanian andMaastrichtian of southern France, from Provence in the East to the valley of the Garonne in the West, have considerably increased our knowledge of the continental vertebrates (fishes, amphibians, turtles, squamates, crocodilians, pterosaurs, dinosaurs, birds and mammals) from that time interval. A succession of faunal assemblages, corresponding to the Early Campanian, the Late Campanian/Early Maastrichtian and the Late Maastrichtian, can now be recognised, with a marked change in the dinosaur fauna during the Maastrichtian, but no clear evidence of decline during the last million years of the Cretaceous. The biogeographical complexity of the Late Cretaceous vertebrate assemblages from southwestern Europe is underlined. Ces dernières années, des prospections et des fouilles systématiques dans le Campanien et leMaastrichtien continentaux du Sud de la France, de la Provence à l'Est à la vallée de la Garonne à l'Ouest, ont considérablement augmenté notre connaissance des vertébrés continentaux (poissons, amphibiens, tortues, squamates, crocodiliens, ptérosaures, dinosaures, oiseaux et mammifères) de cette période. Une succession d'assemblages fauniques, correspondant au Campanien inférieur, au Campanien supérieur/Maastrichtien inférieur et au Maastrichtien supérieur, peut désormais être reconnue, avec un changement marqué dans la faune dinosaurienne au cours du Maastrichtien, mais pas de preuve claire d'un déclin pendant les derniers millions d'années du Crétacé. La complexité biogéographique des assemblages de vertébrés du Crétacé supérieur du Sud-Ouest de l'Europe est soulignée.

Assessment of trophic structure of Cretaceous communities based on stable nitrogen isotope analyses

New δ 15 N data suggest the retention of an indigenous signal in ancient high molecular weight organic material. These data open the possibility of obtaining new paleoecological information, based on isotopic analyses, on ancient, well-preserved fossil communities. Stable carbon and nitrogen isotope analyses were performed on high molecular weight organic material isolated from 22 taxa of Late Cretaceous vertebrates (Judith River Formation, Alberta,Canada). The majority of δ 13 C and δ 15 N values (-27‰ to -23‰ and 4‰ to 12‰, for δ 13 C and δ 15 N, respectively) are similar to those reported for modern consumers. An assessment of trophic levels based on δ 15 N is consistent with previous interpretations of food web structure derived from paleoecological interpretations. Among terrestrial consumers, carnivorous theropods (tyrannosaurids and dromaeosaurids) have high δ 15 N values (6.6‰ ±0.4‰ and 7.9‰, respectively) relative to those of the dominant megaherbivore (hadrosaurids, 4.7‰ ±0.5‰). Within aquatic environments, the values of δ 15 N of the bowfin Amia (11.6‰) and plesiosaur (11.0‰),distinguish the piscivorous tendencies of these organisms from those of tower trophic level consumers such as the benthic feeding sturgeon Acipenser and the turtle Aspideretes (δ 15 N = 5.1‰ and 4.5‰, respectively). The correlation in trophic position between δ 15 N values and paleoecological evidence is unlikely to be coincidental.

Baptornissp. (Aves: Hesperornithiformes) from the Judith River Formation (Campanian) of Saskatchewan, Canada

A vertebra from the Judith River Formation (Campanian) of Saskatchewan, found with other Upper Cretaceous vertebrate remains, is referred to the loon-like hesperornithiformBaptornis, and is the first recorded occurrence of this genus from continental deposits. It is also the first bird described from the Judith River Formation of western Canada.

A new link between theropods and birds from the Cretaceous of Mongolia

THE origin of birds from theropod dinosaurs1 is now broadly accepted, but there is little agreement as to which group of theropods is closest to avian ancestry2. Here we report the discovery of a fragmentary skull in a collection of Late Cretaceous verte-brates from Mongolia. The skull presents a novel combination of theropod and primitive avian characters, which suggests that it belongs to the closest of the known non-avian relatives of Archaeopteryx and other birds. The new fossil shows consistent similarities to the troodontid theropods, for whom close avian relationships have been proposed3, and to Baryonyx4 and Spinosaurus5, two unusual theropods from the Lower Cretaceous of England and the lowermost Upper Cretaceous of Africa, respec-tively.

Note on the occurrence of the marine turtle Desmatochelys (Reptilia: Chelonioidea) from the Upper Cretaceous of Vancouver Island

An incomplete specimen of Desmatochelys cf. D. lowi (Reptilia: Chelonioidea) from the Trent River Formation (Santonian–Campanian) of the Comox Basin of eastern Vancouver Island is the first documented account of Cretaceous marine vertebrates from the Pacific coast of Canada. It represents both stratigraphic and geographic range extensions for the genus Desmatochelys.

Early Cretaceous (Comanchean) vertebrates of central Texas

ABSTRACT Vertebrates from the Comanche Series (Lower Cretaceous) in central Texas occur in the superposed Twin Mountains, Glen Rose, and Paluxy formations. Stratigraphie position and relationship to marine units are more clearly defined for the central Texas localities than for the classic mammal-producing sites in the Antlers Formation of north-central Texas. The diverse terrestrial to marine faunas include new records for the ray Rhinobatos, a ptychodont (cf. Hylaeobatis ornata), and the salmoniform Enchodus. Anurans, salamanders, lacertilians, and mammals representing early forms relevant to the emergence of extant higher taxa are present but fragmentary. Crocodilians are represented by at least three taxa and theropods by more than three. Eight species of mammals have been named from the Comanche Series, with perhaps as many as four other unnamed species represented. Paleoenvironments appear to control the distribution of taxa: dinosaurs are found in coastal settings and are abundant in some terrestri...

Tertiary dinosaurs in South America? A reply to some of Van Valen's assertions

The discussion of the age of some South American Late Cretaceous fossil vertebrate localities by Van Valen led this author to admit the possible persistence of Dinosaurs at the base of the Paleocene. Van Valen's arguments resting on the selachians are reviewed and it can be asserted that the selachian‐bearing localities of the El Molino Formation of Bolivia are Cretaceous and not Tertiary.

Vertebrate extinctions and survival across the Cretaceous-Tertiary boundary

A critical analysis of the fossil vertebrate record across the Cretaceous-Tertiary boundary shows that the available evidence is far less accurate than that concerning invertebrates and microfossils. Far-reaching conclusions have been drawn from generalisations about vertebrate extinctions in the continental realm based on the local record from western North America, but little is known about patterns of terminal Cretaceous vertebrate extinctions in other parts of the world, and even the western North American record is ambiguous. Despite this unsatisfactory record, it clearly appears that terminal Cretaceous vertebrate extinctions were highly selective, with some groups (e.g. dinosaurs) becoming completely extinct, whereas others seem to be virtually unaffected. This argues against devastating catastrophes of the kind postulated by some recent impact scenarios. However, the survival of groups known to be sensitive to climatic deterioration (such as crocodilians and other non-dinosaurian reptiles) indicates that alternative hypotheses involving gradual but fairly important climatic changes on a world-wide scale are not convincing either. The pattern of extinction and survival among vertebrates across the Cretaceous-Tertiary boundary may be explained as a consequence of the disruption of some food chains following a crisis in the plant kingdom, which itself may have been the result of the atmospheric consequences of unusual extraterrestrial or internal events.

Late Cretaceous Vertebrate Fossils from the North Slope of Alaska and Implications for Dinosaur Ecology: Comment &amp; Reply

Late Cretaceous Vertebrate Fossils from the North Slope of Alaska and Implications for Dinosaur Ecology: Comment &amp; Reply

Correlation and Taphonomy of Late Cretaceous Vertebrate Localities in Fruitland and Kirtland Formations, San Juan Basin, New Mexico: ABSTRACT

Correlation and Taphonomy of Late Cretaceous Vertebrate Localities in Fruitland and Kirtland Formations, San Juan Basin, New Mexico: ABSTRACT