1
|
Rollot Y, Evers SW, Cifelli RL, Joyce WG. New insights into the cranial osteology of the Early Cretaceous paracryptodiran turtle Lakotemys australodakotensis. PeerJ 2022; 10:e13230. [PMID: 35437477 PMCID: PMC9013237 DOI: 10.7717/peerj.13230] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 03/16/2022] [Indexed: 01/12/2023] Open
Abstract
Lakotemys australodakotensis is an Early Cretaceous paracryptodire known from two shells and a skull from the Lakota Formation of South Dakota, USA. Along with the Early Cretaceous Arundelemys dardeni and the poorly known Trinitichelys hiatti, Lakotemys australodakotensis is generally retrieved as an early branching baenid, but more insights into the cranial anatomy of these taxa is needed to obtain a better understanding of paracryptodiran diversity and evolution. Here, we describe the skull of Lakotemys australodakotensis using micro-computed tomography to provide the anatomical basis for future phylogenetic analyses that will be needed to investigate more precisely the intrarelationships of Paracryptodira. Preliminary comparisons reveal that the cranial anatomy of Lakotemys australodakotensis is very similar to that of the Aptian-Albian basal baenid Arundelemys dardeni, that both taxa exhibit a remarkable combination of derived characters found in baenodds and characters found in non-baenid paracryptodires, particularly Pleurosternidae, and that Lakotemys australodakotensis is the only known baenid to date to possess a canal for the palatine artery.
Collapse
Affiliation(s)
- Yann Rollot
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
| | - Serjoscha W. Evers
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
| | | | - Walter G. Joyce
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
| |
Collapse
|
2
|
Suarez CA, Frederickson J, Cifelli RL, Pittman JG, Nydam RL, Hunt-Foster RK, Morgan K. A new vertebrate fauna from the Lower Cretaceous Holly Creek Formation of the Trinity Group, southwest Arkansas, USA. PeerJ 2021; 9:e12242. [PMID: 34721970 PMCID: PMC8542373 DOI: 10.7717/peerj.12242] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 09/12/2021] [Indexed: 11/20/2022] Open
Abstract
We present a previously discovered but undescribed late Early Cretaceous vertebrate fauna from the Holly Creek Formation of the Trinity Group in Arkansas. The site from the ancient Gulf Coast is dominated by semi-aquatic forms and preserves a diverse aquatic, semi-aquatic, and terrestrial fauna. Fishes include fresh- to brackish-water chondrichthyans and a variety of actinopterygians, including semionotids, an amiid, and a new pycnodontiform, Anomoeodus caddoi sp. nov. Semi-aquatic taxa include lissamphibians, the solemydid turtle Naomichelys, a trionychid turtle, and coelognathosuchian crocodyliforms. Among terrestrial forms are several members of Dinosauria and one or more squamates, one of which, Sciroseps pawhuskai gen. et sp. nov., is described herein. Among Dinosauria, both large and small theropods (Acrocanthosaurus, Deinonychus, and Richardoestesia) and titanosauriform sauropods are represented; herein we also report the first occurrence of a nodosaurid ankylosaur from the Trinity Group. The fauna of the Holly Creek Formation is similar to other, widely scattered late Early Cretaceous assemblages across North America and suggests the presence of a low-diversity, broadly distributed continental ecosystem of the Early Cretaceous following the Late Jurassic faunal turnover. This low-diversity ecosystem contrasts sharply with the highly diverse ecosystem which emerged by the Cenomanian. The contrast underpins the importance of vicariance as an evolutionary driver brought on by Sevier tectonics and climatic changes, such as rising sea level and formation of the Western Interior Seaway, impacting the early Late Cretaceous ecosystem.
Collapse
Affiliation(s)
- Celina A Suarez
- Department of Geosciences, University of Arkansas at Fayetteville, Fayetteville, Arkansas, USA
| | - Joseph Frederickson
- Weis Earth Science Museum, University of Wisconsin Oshkosh Fox Cities Campus, Menasha, WI, USA
| | - Richard L Cifelli
- Department of Vertebrate Paleontology, Sam Noble Oklahoma Museum of Natural History, University of Oklahoma, Norman, OK, USA
| | | | - Randall L Nydam
- Arizona College of Osteopathic Medicine, Midwestern University, Glendale, Arizona, USA
| | | | - Kirsty Morgan
- Department of Geosciences, University of Arkansas at Fayetteville, Fayetteville, Arkansas, USA
| |
Collapse
|
3
|
Abstract
Triconodontidae are considered the first carnivorous crown mammals. A virtual reconstruction of the masticatory cycle in the Late Jurassic Priacodon showed that triconodontid dental function is characterized by precise cutting on elongated crests. The combination of traits linked to both carnivorous diets (e.g. fore-aft cutting edges) and insectivorous diets (transverse crests and lobes) suggests a varied faunivorous diet appropriate to the small body size of most triconodontids. Total length of molar shear decreased with wear, suggesting a dietary shift during ontogeny. Embrasure occlusion is confirmed for P. fruitaensis as indicated by premolar positioning, facet orientation, and collision areas. Embrasure occlusion is considered a general feature of all Eutriconodonta, whereas the previously assumed Morganucodon-like pattern is limited to few early mammaliaforms. Unlike modern carnivores, significant roll of around 10° of the active hemimandible occurred during the power stroke. Roll was likely passive in Triconodontidae in contrast to active roll described for extant therians. The triconodontid molar series was highly uniform and adapted to a precise fit, with self-sharpening lower molar cusps. Whereas the uniformity ensured good cutting capabilities, it likely put the dentition under greater constraints, conserving the highly stereotyped nature of triconodontid molars for 60-85 Ma.
Collapse
Affiliation(s)
- Kai R K Jäger
- Section Palaeontology, Institute of Geosciences, Rheinische Friedrich-Wilhelms-Universität Bonn, Nussallee 8, 53115, Bonn, Germany.
| | - Richard L Cifelli
- Oklahoma Museum of Natural History, 2401 Chautauqua Ave, Norman, OK, 73072, USA
| | - Thomas Martin
- Section Palaeontology, Institute of Geosciences, Rheinische Friedrich-Wilhelms-Universität Bonn, Nussallee 8, 53115, Bonn, Germany
| |
Collapse
|
4
|
Frederickson JA, Engel MH, Cifelli RL. Niche Partitioning in Theropod Dinosaurs: Diet and Habitat Preference in Predators from the Uppermost Cedar Mountain Formation (Utah, U.S.A.). Sci Rep 2018; 8:17872. [PMID: 30552378 PMCID: PMC6294763 DOI: 10.1038/s41598-018-35689-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 11/08/2018] [Indexed: 11/09/2022] Open
Abstract
We explore hypothetical ecologies to explain diversity among predatory dinosaurs in North America's medial Cretaceous, based on occurrence, tooth morphology, and stable isotope analysis. The Mussentuchit local fauna, Utah, USA, is among the best-known terrestrial vertebrate assemblages from the Cretaceous. Study samples include teeth from six microvertebrate sites, ranging in depositional setting from distal floodplain to channel lags. We recognize four theropod morphotypes: a comparatively large theropod (morph 1), a medium-sized dromaeosaurid (morph 2), a small dromaeosaurid (morph 3), and a tooth-morph similar to the genus Richardoestesia (morph 4). These four morphotypes vary significantly in mean size, from 15.1 mm in the largest theropod to 3.7 mm in Richardoestesia. Further, tooth representation from two of the best-sampled microsites (representing a channel/splay and floodplain deposit) show differing patterns of abundances with morphs 1 and 3 having roughly the same abundance in both sites, while morph 2 was more abundant in the floodplain setting and morph 4 was more abundant in the channel/splay. Stable isotope analysis (δ13C; δ18O) of tooth carbonate from the theropod morphotypes, goniopholidid crocodilians, and matrix (to test for diagenesis) from these sites were also analyzed. The theropods show modest differences in δ13C values between each other, with carbonate from the teeth of morphs 1, 3, and 4 being enriched in 13C for the channel/splay relative to the floodplain environments, possibly indicative of dietary plasticity in these species. We hypothesize that these data indicate that the Mussentuchit theropods had different niches within the predator guild, suggesting plausible means by which ecospace was divided among the predatory dinosaurs of the Mussentuchit local fauna.
Collapse
Affiliation(s)
- J A Frederickson
- Department of Biological Sciences, Southwestern Oklahoma State University, 100 Campus Drive, Weatherford, OK, 73096, USA. .,Department of Biology, University of Oklahoma, Norman, Oklahoma, 73072, USA. .,Sam Noble Museum, 2401 Chautauqua Avenue, Norman, Oklahoma, 73072, USA.
| | - M H Engel
- School of Geology and Geophysics, University of Oklahoma, Norman, Oklahoma, 73072, USA
| | - R L Cifelli
- Department of Biology, University of Oklahoma, Norman, Oklahoma, 73072, USA.,Sam Noble Museum, 2401 Chautauqua Avenue, Norman, Oklahoma, 73072, USA
| |
Collapse
|
5
|
Affiliation(s)
- R L Cifelli
- Department of Vertebrate Paleontology, American Museum of Natural History, New York, New York, 10024
| |
Collapse
|
6
|
Abstract
One hundred years ago, Alfred Wegener laid the foundations for the theory of plate tectonics
Collapse
Affiliation(s)
- Marco Romano
- Dipartimento di Scienze della Terra, Sapienza, Università di Roma, P.le A. Moro 5, 00185 Roma, Italy.
| | | |
Collapse
|
7
|
Affiliation(s)
- Marco Romano
- Dipartimento di Scienze della Terra, "Sapienza" Università di Roma, Rome, Italy.,Sam Noble Museum, Norman, OK, USA
| | | |
Collapse
|
8
|
Farke AA, Maxwell WD, Cifelli RL, Wedel MJ. A Ceratopsian Dinosaur from the Lower Cretaceous of Western North America, and the Biogeography of Neoceratopsia. PLoS One 2014; 9:e112055. [PMID: 25494182 PMCID: PMC4262212 DOI: 10.1371/journal.pone.0112055] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 09/22/2014] [Indexed: 11/18/2022] Open
Abstract
The fossil record for neoceratopsian (horned) dinosaurs in the Lower Cretaceous of North America primarily comprises isolated teeth and postcrania of limited taxonomic resolution, hampering previous efforts to reconstruct the early evolution of this group in North America. An associated cranium and lower jaw from the Cloverly Formation (?middle–late Albian, between 104 and 109 million years old) of southern Montana is designated as the holotype for Aquilops americanus gen. et sp. nov. Aquilops americanus is distinguished by several autapomorphies, including a strongly hooked rostral bone with a midline boss and an elongate and sharply pointed antorbital fossa. The skull in the only known specimen is comparatively small, measuring 84 mm between the tips of the rostral and jugal. The taxon is interpreted as a basal neoceratopsian closely related to Early Cretaceous Asian taxa, such as Liaoceratops and Auroraceratops. Biogeographically, A. americanus probably originated via a dispersal from Asia into North America; the exact route of this dispersal is ambiguous, although a Beringian rather than European route seems more likely in light of the absence of ceratopsians in the Early Cretaceous of Europe. Other amniote clades show similar biogeographic patterns, supporting an intercontinental migratory event between Asia and North America during the late Early Cretaceous. The temporal and geographic distribution of Upper Cretaceous neoceratopsians (leptoceratopsids and ceratopsoids) suggests at least intermittent connections between North America and Asia through the early Late Cretaceous, likely followed by an interval of isolation and finally reconnection during the latest Cretaceous.
Collapse
Affiliation(s)
- Andrew A. Farke
- Raymond M. Alf Museum of Paleontology, Claremont, California, United States of America
- Sam Noble Oklahoma Museum of Natural History, Norman, Oklahoma, United States of America
- * E-mail:
| | - W. Desmond Maxwell
- Department of Biological Sciences, University of the Pacific, Stockton, California, United States of America
- Sam Noble Oklahoma Museum of Natural History, Norman, Oklahoma, United States of America
| | - Richard L. Cifelli
- Sam Noble Oklahoma Museum of Natural History, Norman, Oklahoma, United States of America
| | - Mathew J. Wedel
- Sam Noble Oklahoma Museum of Natural History, Norman, Oklahoma, United States of America
- College of Podiatric Medicine, Western University of Health Sciences, Pomona, California, United States of America
| |
Collapse
|
9
|
|
10
|
Affiliation(s)
- Richard L Cifelli
- Oklahoma Museum of Natural History and Department of Zoology, University of Oklahoma, Norman, OK 73072, USA.
| | | |
Collapse
|
11
|
Abstract
Marsupials, placentals and their close therian relatives possess complex (tribosphenic) molars that are capable of versatile occlusal functions. This functional complex is widely thought to be a key to the early diversification and evolutionary success of extant therians and their close relatives (tribosphenidans). Long thought to have arisen on northern continents, tribosphenic mammals have recently been reported from southern landmasses. The great age and advanced morphology of these new mammals has led to the alternative suggestion of a Gondwanan origin for the group. Implicit in both biogeographic hypotheses is the assumption that tribosphenic molars evolved only once in mammalian evolutionary history. Phylogenetic and morphometric analyses including these newly discovered taxa suggest a different interpretation: that mammals with tribosphenic molars are not monophyletic. Tribosphenic molars evolved independently in two ancient (holotherian) mammalian groups with different geographic distributions during the Jurassic/Early Cretaceous: an australosphenidan clade endemic to Gondwanan landmasses, survived by extant monotremes; and a boreosphenidan clade of Laurasian continents, including extant marsupials, placentals and their relatives.
Collapse
Affiliation(s)
- Z X Luo
- Section of Vertebrate Paleontology, Carnegie Museum of Natural History, Pittsburgh, Pennsylvania 15213, USA
| | | | | |
Collapse
|
12
|
|
13
|
Abstract
The main groups of living mammals, marsupials and eutherians, are presumed to have diverged in the Early Cretaceous, but their early history and biogeography are poorly understood. Dental remains have suggested that the eutherians may have originated in Asia, spreading to North America in the Late Cretaceous, where an endemic radiation of marsupials was already well underway. Here I describe a new tribosphenic mammal (a mammal with lower molar heels that are three-cusped and basined) from the Early Cretaceous of North America, based on an unusually complete specimen. The new taxon bears characteristics (molarized last premolar, reduction to three molars) otherwise known only for Eutheria among the tribosphenic mammals. Morphometric analysis and character comparisons show, however, that its molar structure is primitive (and thus phylogenetically uninformative), emphasizing the need for caution in interpretation of isolated teeth. The new mammal is approximately contemporaneous with the oldest known Eutheria from Asia. If it is a eutherian, as is indicated by the available evidence, then this group was far more widely distributed in the Early Cretaceous than previously appreciated. An early presence of Eutheria in North America offers a potential source for the continent's Late Cretaceous radiations, which have, in part, proven difficult to relate to contemporary taxa in Asia.
Collapse
Affiliation(s)
- R L Cifelli
- Oklahoma Museum of Natural History and Department of Zoology, University of Oklahoma, Norman, Oklahoma 73019, USA
| |
Collapse
|
14
|
|
15
|
Cifelli RL, Kirkland JI, Weil A, Deino AL, Kowallis BJ. High-precision 40Ar/39Ar geochronology and the advent of North America's Late Cretaceous terrestrial fauna. Proc Natl Acad Sci U S A 1997; 94:11163-7. [PMID: 9326579 PMCID: PMC23402 DOI: 10.1073/pnas.94.21.11163] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
A densely sampled, diverse new fauna from the uppermost Cedar Mountain Formation, Utah, indicates that the basic pattern of faunal composition for the Late Cretaceous of North America was already established by the Albian-Cenomanian boundary. Multiple, concordant 40Ar/39Ar determinations from a volcanic ash associated with the fauna have an average age of 98.39 +/- 0.07 million years. The fauna of the Cedar Mountain Formation records the first global appearance of hadrosaurid dinosaurs, advanced lizard (e.g., Helodermatidae), and mammal (e.g., Marsupialia) groups, and the first North American appearance of other taxa such as tyrannosaurids, pachycephalosaurs, and snakes. Although the origin of many groups is unclear, combined biostratigraphic and phylogenetic evidence suggests an Old World, specifically Asian, origin for some of the taxa, an hypothesis that is consistent with existing evidence from tectonics and marine invertebrates. Large-bodied herbivores are mainly represented by low-level browsers, ornithopod dinosaurs, whose radiations have been hypothesized to be related to the initial diversification of angiosperm plants. Diversity at the largest body sizes (>10(6) g) is low, in contrast to both preceding and succeeding faunas; sauropods, which underwent demise in the Northern hemisphere coincident with the radiation of angiosperms, apparently went temporarily unreplaced by other megaherbivores. Morphologic and taxonomic diversity among small, omnivorous mammals, multituberculates, is also low. A later apparent increase in diversity occurred during the Campanian, coincident with the appearance of major fruit types among angiosperms, suggesting the possibility of adaptive response to new resources.
Collapse
Affiliation(s)
- R L Cifelli
- Oklahoma Museum of Natural History and Department of Zoology, University of Oklahoma, Norman, OK 73019, USA
| | | | | | | | | |
Collapse
|
16
|
Abstract
Dog-like marsupials (superfamily Borhyaenoidea) were the largest predacious mammals during the Tertiary period in South America. They are critical to our understanding of marsupial origin, phylogeny and palaeobiogeography because they have been related to various marsupial lineages of several continents: didelphoids (mainly New World, but also Europe, Asia and Africa), pediomyid, stagodontids (North America), dasyuroids (Australia) and deltatheroidans (predominantly Asian). These relationships, based mainly on dental morphology, have been discussed and rejected several times. Here we report the discovery of exceptionally well preserved skulls and skeletons, referrable to the didelphoid Andinodelphys, which shed new light on the phylogenetic and palaeobiogeographic origin of dog-like marsupials. The skulls of Mayulestes (boryhyaenoid), Andinodelphys and Pucadelphys (didelphoids) from the early Palaeocene epoch of Bolivia are the oldest known for American marsupials. Comparison of their basicranial anatomy suggests that dog-like marsupials are closely related to an early didelphimorphian radiation in South America, rather than to Asiatic (deltatheroidan), North American (stagodontid), or Australian (dasyuroid) lineages.
Collapse
Affiliation(s)
- C de Muizon
- URA 12 CNRS, Muséum National d'Histoire Naturelle, Laboratoire de Paléontologie, Paris, France
| | | | | |
Collapse
|
17
|
|
18
|
Cifelli RL. Application of Fitted Polynomial Functions to Modeling Contours Derived from Mammalian Mandibular and Dental Morphology. American Midland Naturalist 1996. [DOI: 10.2307/2426741] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
19
|
Abstract
A mammal from the Early Cretaceous of the western United States, represented by a lower jaw exceptional in its completeness, presents unambiguous evidence of postcanine dental formula in an Early Cretaceous marsupial-like mammal, and prompts a reconsideration of the early evolution of marsupial dental characters. A marsupial postcanine dental formula (three premolars and four molars) and several marsupial-like features of the lower molars are present in the new taxon, but a hallmark specialization of marsupials (twinning of the hypoconulid and entoconid on lower molars) is lacking. This, coupled with recent evidence from the Late Cretaceous of the western United States, suggests that the distinctive marsupial dental formula evolved prior to the most characteristic specialization of lower molars and that apomorphies presumed to be diagnostic of the upper molars (such as auxiliary stylar cusps) were relatively more recent developments in marsupial history. Dental evidence supports the monophyly of higher (tribosphenic) mammals and suggests that the predominantly Old World Deltatheroida, recently proposed as a sister taxon to marsupials, represents a primitive and unrelated group of higher mammals; by this interpretation, early marsupials and their presumed close relatives are restricted to North America. This, together with the hypothesized relationships of South American/Australian marsupials (in the context of the North American Cretaceous radiation) and evidence from the fossil record of South America, in turn supports a North American origin for the group.
Collapse
Affiliation(s)
- R L Cifelli
- Oklahoma Museum of Natural History, University of Oklahoma, Norman 73019
| |
Collapse
|
20
|
|
21
|
|
22
|
|
23
|
Novacek MJ, McKenna MC, Neff NA, Cifelli RL. Evidence from earliest known erinaceomorph basicranium that insectivorans and primates are not closely related. Nature 1983; 306:683-4. [PMID: 6656867 DOI: 10.1038/306683a0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The erinaceomorph insectivorans, which include the living hedgehog and a diversity of archaic taxa, have long been considered to be close relatives or direct ancestors of primates and a variety of other placental mammal orders. We report here on the oldest known erinaceomorph basicranium which provides new evidence against the view that primates and erinaceomorphs share a close common ancestry.
Collapse
|