scholarly journals A new elasmosaurid (Sauropterygia: Plesiosauria) from the non-marine to paralic Dinosaur Park Formation of southern Alberta, Canada

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10720
Author(s):  
James A. Campbell ◽  
Mark T. Mitchell ◽  
Michael J. Ryan ◽  
Jason S. Anderson
Keyword(s):  
Small Body ◽  
Niche Partitioning ◽  
Estuarine Sediments ◽  
Character State ◽  
New Taxon ◽  
Distinctive Character ◽  
Research Attention ◽  
Marine Deposits ◽  
Southern Alberta ◽  
Dinosaur Park Formation

Elasmosaurid plesiosaurian remains have been documented from non-marine to paralic (fluvial to estuarine) sediments of the upper Campanian Dinosaur Park Formation (DPF) of southern Alberta since 1898. Despite this long collection history, this material has received relatively little research attention, largely due to the highly fragmentary nature of most recovered specimens. However, this assemblage is significant, as it constitutes a rare occurrence of plesiosaurian remains in a non-marine depositional environment. This study reports on a recently collected and prepared specimen, which represents the most complete elasmosaurid yet collected from the DPF. This specimen preserves the trunk region, the base of the neck and tail, a partial fore and hind limb, and tooth, and is sufficiently complete to be assigned as the holotype of a new genus and species. This new taxon is diagnosed by a distinctive character state combination including a boomerang-shaped clavicular arch with acute anterior process, convex anterolateral margin, deeply embayed posterior margin, and pronounced ventral keel, together with the presence of 22 dorsal vertebrae, and the anterior dorsal centra bearing a ventral notch. The DPF plesiosaurian fossils were recovered from both estuarine/bay and fluvial palaeochannel sediments. The holotype skeleton represents an osteologically mature individual with an estimated body length of around 5 m, although the largest referred DPF elasmosaurid might have been closer to 7 m, which is considerably larger than other plesiosaurians reported from non-marine deposits. This suggests small-body lengths relative to typical elasmosaurids from marine settings, but is consistent with other plesiosaurians recovered from non-marine sediments. The identification of a distinct elasmosaurid taxon in the DPF might be evidence of niche-partitioning among the predominantly oceanic members of the ubiquitous plesiosaurian clade.

scholarly journals A new species of Xyliphius, a rarely sampled banjo catfish (Siluriformes: Aspredinidae) from the rio Tocantins-Araguaia system

2010 ◽  
Vol 8 (1) ◽  
pp. 105-112 ◽  
Author(s):  
Carlos A Figueiredo ◽  
Marcelo R Britto
Keyword(s):  
New Species ◽  
Conservation Status ◽  
River System ◽  
Character State ◽  
New Taxon ◽  
Posterior Border ◽  
Lower Lip ◽  
Araguaia River ◽  
State Variation ◽  
A New Species

Xyliphius anachoretes, a new species of aspredinid catfish is described from the Tocantins-Araguaia River system. Xyliphius anachoretes is diagnosed by the presence of six developed retrorse serrae on posterior border of pectoral-fin spine, presence of papillae on the lower lip bearing minute branches, and only two dorsal procurrent rays. Comments about the informativeness of character-state variation among Xyliphius species and aspredinid related genera are furnished. Also, a brief discussion about conservation status of the new taxon is made.

scholarly journals A new species of Ampharete (Annelida: Ampharetidae) from the West Shetland shelf (NE Atlantic Ocean), with two updated keys to the species of the genus in North Atlantic waters

2019 ◽  
Author(s):  
Julio Parapar ◽  
Juan MOREIRA ◽  
Ruth BARNICH
Keyword(s):  
North Atlantic ◽  
Small Body ◽  
New Taxon ◽  
Ne Atlantic ◽  
The West ◽  
The North ◽  
Joint Nature Conservation Committee ◽  
Ne Atlantic Ocean ◽  
Micro Morphology ◽  
A New Species

Ampharete oculicirrata sp. nov. (Annelida: Ampharetidae) is described from samples collected by the Joint Nature Conservation Committee and Marine Scotland Science, in the West Shetland Shelf NCMPA in the NE Atlantic. This species is characterised by a very small body size, thin and slender paleae, twelve thoracic and eleven abdominal uncinigers, presence of eyes both in the prostomium and the pygidium, the latter provided with a pair of long lateral cirri. The external micro-morphology of the new taxon was studied using scanning electron microscopy and compared with species described or reported from the North Atlantic. Two complementary keys to all species of Ampharete in the area are also provided.

The first record of spiral coprolites from the Dinosaur Park Formation (Judith River Group, Upper Cretaceous) southern Alberta, Canada

1995 ◽  
Vol 69 (6) ◽  
pp. 1191-1194 ◽  
Author(s):  
Clive E. Coy
Keyword(s):  
North America ◽  
Upper Cretaceous ◽  
First Record ◽  
Niobrara Formation ◽  
Southern Alberta ◽  
Dinosaur Park Formation

Spiral coprolites from the Upper Cretaceous of North America are poorly known. Enterospirae (fossilized intestines) reported from the Upper Cretaceous Niobrara Formation of western Kansas (Stewart, 1978) were disputed by McAllister (1985), who felt they represented spiral coprolites similar to those described from the Permian by Neumayer (1904). Previously described coprolites from the Upper Cretaceous of Alberta are small, unstructured, ellipsoidal forms thought to derive from a crocodilian or terrestrial, carnivorous reptile of necrophagic or piscivorous habits (Waldman, 1970; Waldman and Hopkins, 1970).

scholarly journals A new species of troodontid theropod (Dinosauria: Maniraptora) from the Horseshoe Canyon Formation (Maastrichtian) of Alberta, Canada

2017 ◽  
Vol 54 (8) ◽  
pp. 813-826 ◽  
Author(s):  
David C. Evans ◽  
Thomas M. Cullen ◽  
Derek W. Larson ◽  
Adam Rego
Keyword(s):  
New Species ◽  
North America ◽  
Alpha Diversity ◽  
Width Ratio ◽  
New Taxon ◽  
Lateral Region ◽  
Morphometric Analyses ◽  
Dinosaur Park Formation ◽  
Horseshoe Canyon Formation ◽  
A New Species

Troodontid material from the Maastrichtian of North America is extremely rare, beyond isolated teeth from microvertebrate sites. Here we describe troodontid frontals from the early Maastrichtian Horseshoe Canyon Formation (Horsethief Member). The most complete specimen, TMP 1993.105.0001, is notably foreshortened and robust when compared with numerous specimens referred to Troodon from the Dinosaur Park Formation, and exhibits several characteristics that distinguish it from other Late Cretaceous troodontids. Morphometric analyses reinforce shape differences between TMP 1993.105.0001 and other North American troodontids, and show that proportional differences are independent of size. We therefore erect a new taxon, Albertavenator curriei gen. et sp. nov., which is diagnosed by the following autapomorphies: (1) primary supraciliary foramen is truncated anteriorly by the lacrimal contact; (2) superficial (ectocranial) surface of the frontal proportionally shorter than all known troodontids, with a length to width ratio under 1.3; and (3) frontoparietal contact in which an enlarged lappet of the frontal extends medially to extensively overlap the lateral region of the anteromedial process of the parietal. Interestingly, tooth and jaw morphology from the single relatively complete dentary recovered from the Horseshoe Canyon cannot be distinguished from dentaries and teeth from the Dinosaur Park Formation. If the dentary and teeth from the Horsethief Member of the Horseshoe Canyon Formation prove to belong to A. curriei, extensive overlap in tooth morphology between the Dinosaur Park and Horseshoe Canyon formations reinforces the notion that tooth morphotypes do not exhibit strong correspondence to species alpha diversity, and may encompass multiple closely related taxa.

scholarly journals A new species of troodontid theropod (Dinosauria: Maniraptora) from the Horseshoe Canyon Formation (Maastrichtian) of Alberta, Canada

2018 ◽  
Author(s):  
David Evans ◽  
Thomas Cullen ◽  
Derek Larson ◽  
Adam Rego
Keyword(s):  
New Species ◽  
North America ◽  
Alpha Diversity ◽  
Width Ratio ◽  
New Taxon ◽  
Lateral Region ◽  
Morphometric Analyses ◽  
Dinosaur Park Formation ◽  
Horseshoe Canyon Formation ◽  
A New Species

Troodontid material from the Maastrichtian of North America is extremely rare, beyond isolated teeth from microvertebrate sites. Here we describe troodontid frontals from the early Maastrichtian Horseshoe Canyon Formation (Horsethief Member). The most complete specimen, TMP 1993.105.0001, is notably foreshortened and robust when compared with numerous specimens referred to Troodon from the Dinosaur Park Formation, and exhibits several characteristics that distinguish it from other Late Cretaceous troodontids. Morphometric analyses reinforce shape differences between TMP 1993.105.0001 and other North American troodontids, and show that proportional differences are independent of size. We therefore erect a new taxon, Albertavenator curriei gen. et sp. nov., which is diagnosed by the following autapomorphies: (1) primary supraciliary foramen is truncated anteriorly by the lacrimal contact; (2) superficial (ectocranial) surface of the frontal proportionally shorter than all known troodontids, with a length to width ratio under 1.3; and (3) frontoparietal contact in which an enlarged lappet of the frontal extends medially to extensively overlap the lateral region of the anteromedial process of the parietal. Interestingly, tooth and jaw morphology from the single relatively complete dentary recovered from the Horseshoe Canyon cannot be distinguished from dentaries and teeth from the Dinosaur Park Formation. If the dentary and teeth from the Horsethief Member of the Horseshoe Canyon Formation prove to belong to A. curriei, extensive overlap in tooth morphology between the Dinosaur Park and Horseshoe Canyon formations reinforces the notion that tooth morphotypes do not exhibit strong correspondence to species alpha diversity, and may encompass multiple closely related taxa.

scholarly journals A New Cynodont from the Late Triassic Los Colorados Formation (Argentina, South America) Reveals a Novel Paleobiogeographic Context for Mammalian Ancestors

2021 ◽  
Author(s):  
L. C. GAETANO ◽  
F. ABDALA ◽  
F. D. SEOANE ◽  
A. TARTAGLIONE ◽  
M. SCHULZ ◽  
...  
Keyword(s):  
Data Matrix ◽  
Late Triassic ◽  
Character State ◽  
New Taxon ◽  
X Rays ◽  
Crown Group ◽  
Unique Character ◽  
New Findings ◽  
Micro Tomography ◽  
Important Center

Abstract Probainognathia is a derived lineage of cynodonts which encompass Mammalia as their crown-group. The profuse record of probainognathians from the Carnian of Argentina contrasts with their Norian representation, with only one named species. Here we describe a new probainognathian, Tessellatia bonapartei gen. et sp. nov., from the Norian Los Colorados Formation of the Ischigualasto-Villa Unión Basin of Argentina. The new taxon, represented by a partial cranium with articulated lower jaws, was analyzed through neutron and X-rays micro-tomography (µCT). The high-resolution neutron µCT data allowed the identification of a unique character state combination, including features inaccessible through traditional techniques. We constructed the largest phylogenetic data-matrix of non-mammalian cynodonts. The new species and its sister-taxon, the Brazilian Therioherpeton, are recovered as probainognathians, closely related to Mammaliamorpha. We conducted the first quantitative paleobiogeographic analysis of non-mammalian cynodonts, focusing in probainognathians. The results indicate that Probainognathia and Mammaliamorpha originated in Brazil, which was an important center of diversification during the Triassic. Finally, China is identified as the ancestral area of Mammaliaformes. These new findings, besides adding to the knowledge of the poorly represented Norian cynodonts from the Los Colorados Formation, are significant to improve our understanding of probainognathian diversity, evolution, and paleobiogeographic history.

Relative land-sea-level changes in southeastern England during the Pleistocene

1972 ◽  
Vol 272 (1221) ◽  
pp. 87-98 ◽  
Keyword(s):  
Sea Level ◽  
Sea Level Change ◽  
Estuarine Sediments ◽  
Level Fluctuation ◽  
Sea Level Changes ◽  
Freshwater Sediments ◽  
Marine Deposits ◽  
Level Change ◽  
Lower Pleistocene ◽  
Sea Level Fluctuation

During the Pleistocene, a period covering the last two million years, sea level is known to have risen above and fallen below the present sea level. The evidence for such fluctuations comes from marine and estuarine sediments, including beaches, far above present sea level and from freshwater sediments, beaches and valley systems now submerged. In southeast England there are Lower Pleistocene marine deposits at 183 m O.D . at Netley Heath in Surrey and upper Pleistocene freshwater sediments at - 35 m O.D . in the Channel. Thus we have in this area evidence of an amplitude of sea-level fluctuation relative to the present sea level of some 218 m. While such limits of relative sea-level fluctuation are not so difficult to identify, very considerable difficulties arise in determining the relation of sea-level change to the passage of time, and in the analysis of sea-level change - whether it be a real lowering of sea level relative to land, or an uplift of land relative to sea level. Let us briefly consider each of these two fields of difficulty. To date a particular stand of sea level, we have to know the relation of a particular deposit, say beach or shallow marine sediment to sea level at the time, and we have to know the correlation of this deposit to a part of the sequence of geological events which make up the Pleistocene. Both of these aspects may be problematical. It may not be certain what depth of water a deposit was formed in, and the age and correlation of the deposit may be doubtful.

A new species of terrestrial-breeding frog of the genus Pristimantis (Anura: Terrarana: Craugastoridae) from the eastern Andean slopes of the southern Ecuador

Zootaxa ◽  
2019 ◽  
Vol 4658 (3) ◽  
pp. 509-525 ◽  
Author(s):  
JORGE H. VALENCIA ◽  
FRANCISCO VALLADARES-SUNTASIG ◽  
LUIS TIPANTIZA-TUGUMINAGO ◽  
MANUEL R. DUEÑAS
Keyword(s):  
New Species ◽  
Cloud Forest ◽  
Small Body ◽  
Advertisement Call ◽  
New Taxon ◽  
Adult Males ◽  
Upper Eyelid ◽  
Adult Females ◽  
History Of ◽  
Eye Diameter

A new frog of the genus Pristimantis is described from a montane cloud forest at 9 de Octubre (2°14’52” S, 78°16’37” W; 1778 m) province of Morona Santiago in the upper basin of the Upano River, southeastern Ecuador. The description of the new species is based on the examination of eleven adult males and three adult females. The new taxon can be readily distinguished from other congeneric species that inhabit the eastern Andes of Ecuador by the unique combination of the following characters: small body (adult males SVL 12.0–17.0 mm, adult females SVL 18.5–21.7 mm); skin of dorsum finely shagreen with two subconical scapular tubercles, weak and discontinuous dorsolateral folds in the middle of the back; large tympanum 70–93% of eye diameter; snout subacuminate in dorsal view, rounded in profile; upper eyelid bearing four or five small and flat supraocular tubercles; males lacking vocal slits and nuptial pads; all discs on fingers and toes lanceolate. Additionally, we provide information on the advertisement call and natural history of the new species.

Description of a new species of Teratohyla Taylor (Amphibia: Athesphatanura: Centrolenidae) from north-western Ecuador

Zootaxa ◽  
2009 ◽  
Vol 2227 (1) ◽  
pp. 53-62 ◽  
Author(s):  
DIEGO F. CISNEROS-HEREDIA ◽  
MARIO H. YÁNEZ-MUÑOZ ◽  
H. MAURICIO ORTEGA-ANDRADE
Keyword(s):  
New Species ◽  
Body Size ◽  
Small Body ◽  
New Taxon ◽  
Small Body Size ◽  
The Family ◽  
Lowland Forests ◽  
North Western ◽  
A New Species ◽  
Lateral Profile

We describe a new species of Glassfrog of the family Centrolenidae. This new taxon, Terarohyla sornozai sp. nov., is diagnosed by having a protruding snout in lateral profile, uniform green dorsal colouration in life, concealed prepollex, extensive webbing between the outer fingers, fully webbed toes, and small body size. It inhabits the Non-Seasonal Evergreen Foothill and Lowland forests in the provinces of Esmeraldas, Imbabura, and Pichincha, north-western Ecuador.

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