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Re: [dinosaur] Kalthifrons, new mekosuchine crocodile + new species of Primozygodactylus + more Cenozoic stuff



The new species of Eocene Primozygodactylus  are P. longbrachium  and P. quintus.

(My thanks to Fred Ruhe.)


On Tue, Nov 29, 2016 at 11:01 AM, Ben Creisler <bcreisler@gmail.com> wrote:


Ben Creisler
bcreisler@gmail.com


Some recent Cenozoic archosaur and bird stuff that may be of interest:


Kalthifrons aurivellensis


Adam M. Yates & Neville S. Pledge (2016)

A Pliocene mekosuchine (Eusuchia: Crocodilia) from the Lake Eyre Basin of South Australia.

Journal of Vertebrate Paleontology Article: e1244540

doi:  http://dx.doi.org/10.1080/02724634.2017.1244540 

http://www.tandfonline.com/doi/full/10.1080/02724634.2017.1244540

 

A new genus and species of crocodilian, Kalthifrons aurivellensis, is described from a channel sand deposit incised into the Oligo-Miocene Etadunna Formation on the western shore of Lake Palankarinna in the Lake Eyre Basin, South Australia. The channel sand is interpreted as an outcrop of the Mampuwordu Sand Member of the Tirari Formation, which has been assigned an early Pliocene age. The taxon can be diagnosed by the extremely elongate and narrow anterior process of the frontal pair and a distinctively beveled and laterally expanded prefrontal contribution to the orbit margin. The broadly triangular rostrum, at least partially interlocking dentition, smooth dental carinae, and weak labiolingual compression resemble unspecialized crocodilian species, and it was probably a generalist aquatic predator. It possessed character states that indicate that it was not a member of Crocodylus, and it is referred to the endemic Australasian clade Mekosuchinae. The first overlying unit in the Lake Eyre Basin sequence to produce diagnostic crocodilian remains is the mid- to late Pliocene Pompapillina Member of the Tirari Formation. It contains a true species of Crocodylus but no indication of Kalthifrons aurivellensis or indeed any other mekosuchine, indicating that the latter may have been driven to extinction via competitive replacement.

 

http://zoobank.org/urn:lsid:zoobank.org:pub:C4E93358-D80F-4E4D-B7FF-BFFB93EDCD54


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Free pdf:


Torsten M. Scheyer and Massimo Delfino (2016)

The late Miocene caimanine fauna (Crocodylia: Alligatoroidea) of the Urumaco Formation, Venezuela.

Palaeontologia Electronica 19.3.48A: 1–57

http://palaeo-electronica.org/content/2016/1625-caimanines-from-urumaco-formation

http://palaeo-electronica.org/content/pdfs/657.pdf




The late Miocene Urumaco Formation at Urumaco, Falcón state, Venezuela, is remarkably rich in extinct crocodylians, presenting a diversity hotspot in the Neotropics for the group. Herein, we revise the Caimaninae fauna by including novel fossil material as well as the previously described specimens assignable to this clade. In many instances the taxonomic status of species could be confirmed, which is the case in Caiman brevirostris, Globidentosuchus brevirostris, and Purussaurus mirandai, and novel osteological data is presented to corroborate previous anatomical descriptions. In other cases, specimens needed to be reassigned to different taxa; with material previously identified as Caiman lutescens now considered as belonging to either Caiman latirostris or Caiman wannlangstoni, and material of Melanosuchus fisheri reassigned to Caimaninae aff. Melanosuchus fisheri. Furthermore, Mourasuchus nativus is considered to be a junior synonym of Mourasuchus arendsi herein. This suggests that there are only three species of the duck-billed caimanine Mourasuchus present in the Miocene of South America, having colonised the continent from the northwest (Colombia and Peru) during the middle Miocene and moving to the east and southeast (Venezuela, Brazil and Argentina) in the late Miocene. Other specimens, which were previously identified as belonging to the genus Caiman, lack diagnostic features of the modern genus and are instead considered as Caimaninae indet. Besides improving the knowledge of the late Miocene crocodylians of South America, our results confirm the high taxonomic diversity of the fauna and the outstanding level of sympatry previously reported for the Urumaco Formation.

 

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BIRDS


(I don't have the new species names yet...)


Gerald Mayr (2016)

New species of Primozygodactylus from Messel and the ecomorphology and evolutionary significance of early Eocene zygodactylid birds (Aves, Zygodactylidae).

Historial Biology (advance online publication)

doi:  http://dx.doi.org/10.1080/08912963.2016.1261135  



 

Zygodactylids (Zygodactylidae) are the extinct sister taxon of passerines (Passeriformes) and among the more abundant small arboreal birds in the early Eocene German fossil site Messel. Four species of the taxon Primozygodactylus have previously been identified and here two new species are described. In addition, new fossils of the poorly known P. eunjooae are reported. The fossils corroborate the presence of two very long central tail feathers for Primozygodactylus, and the feathering of the taxon corresponds with that of extant birds foraging in scrub and undergrowth. Species diversity of zygodactylids falls short of that of passerines, the most species-rich extant avian clade, and in bill shapes they also do not reach the diversity seen in extant Passeriformes. Because zygodactylids closely resemble passerines in skeletal morphology, the evolutionary success of passerines is unlikely to be due to particular skeletal features. Passerines and zygodactylids coexisted in Europe from the early Oligocene to the middle Miocene, and both groups probably differed in ecological characteristics. The zygodactyl foot of zygodactylids may have represented an adaptation for clinging to tree trunks, and if nesting in tree cavities, zygodactylids may have succumbed to competition for safe nesting places with avian or mammalian competitors.

 

http://zoobank.org/urn:lsid:zoobank.org:pub:7F142141-7E1F-4568-89BF-E2363D128C36


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Johan A. Gren, Peter Sjövall, Mats E. Eriksson, Rene L. Sylvestersen, Federica Marone, Kajsa G. V. Sigfridsson Clauss, Gavin J. Taylor, Stefan Carlson, Per Uvdal and Johan Lindgren (2016)

Molecular and microstructural inventory of an isolated fossil bird feather from the Eocene Fur Formation of Denmark.

Palaeontology (advance online publication)

DOI: 10.1111/pala.12271

http://onlinelibrary.wiley.com/doi/10.1111/pala.12271/full




An isolated, yet virtually intact contour feather (FUM-1980) from the lower Eocene Fur Formation of Denmark was analysed using multiple imaging and molecular techniques, including field emission gun scanning electron microscopy (FEG-SEM), X-ray absorption spectroscopy and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Additionally, synchrotron radiation X-ray tomographic microscopy (SRXTM) was employed in order to produce a digital reconstruction of the fossil. Under FEG-SEM, the proximal, plumulaceous part of the feather revealed masses of ovoid microstructures, about 1.7 μm long and 0.5 μm wide. Microbodies in the distal, pennaceous portion were substantially smaller (averaging 0.9 × 0.2 μm), highly elongate, and more densely packed. Generally, the microbodies in both the plumulaceous and pennaceous segments were aligned along the barbs and located within shallow depressions on the exposed surfaces. Biomarkers consistent with animal eumelanins were co-localized with the microstructures, to suggest that they represent remnant eumelanosomes (i.e. eumelanin-housing cellular organelles). Additionally, ToF-SIMS analysis revealed the presence of sulfur-containing organics – potentially indicative of pheomelanins – associated with eumelanin-like compounds. However, since there was no correlation between melanosome morphology and sulfur content, we conclude these molecular structures derive from diagenetically incorporated sulfur rather than pheomelanin. Melanosomes corresponding roughly in both size and morphology with those in the proximal part of FUM-1980 are known from contour feathers of extant parrots (Psittaciformes), an avian clade that has previously been reported from the Fur Formation.


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Gerald Mayr & Zbigniew M.  Bochenski (2016)

A skeleton of a small rail from the Rupelian of Poland adds to the diversity of early Oligocene Ralloidea.

Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 282(2): 125-134

DOI: https://doi.org/10.1127/njgpa/2016/0609

http://www.ingentaconnect.com/content/schweiz/njbgeol/2016/00000282/00000002/art00002



The Paleogene fossil record of rails (Sarothruridae and Rallidae) is very scanty. Here we describe a postcranial skeleton of a new rail from the early Oligocene locality Jamna Dolna in southeastern Poland. Although the preservation of the bones is poor, the fossil constitutes the most substantial record of a Paleogene rail. The new specimen is clearly distinguished from the coeval taxon Belgirallus, the only other temporally well-constrained early Oligocene rail. Neither Belgirallus nor the new Oligocene rail appear to have been directly ancestral to the rallid crown group taxa found in Europe today. A well-based phylogenetic placement of the new fossil is, however, impeded by its unusual character mosaic and the fact that morphological apomorphies are unknown for the ralloid subclades resulting from sequence-based phylogenies.



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The official English translation is not yet posted online. The abstract is a rough translation from Russian:



N.V.  Zelenkov (2016)

Revision of non-passeriform birds from Polgárdi (Hungary, Upper Miocene): 2. Galliformes.

Paleontological Journal 2016 (6):  79-90 (Russian edition)

DOI:  10.7868/S0031031X16060167

http://elibrary.ru/item.asp?id=27145980

 

The presence of five taxa is confirmed as the result of a systematic revision of the Galliformes (Aves) from the Upper Miocene of Polgardi. A large pheasant, originally described as Pavo aesculapi phasianoides Janossy, 1991 is placed in the genus Syrmaticus as a valid species S. phasianoides (Janossy, 1991), comb. nov. Small Phasianidae in Polgardi presented four forms: Mioryaba magyarica gen. et sp. nov., Eurobambusicola turolicus gen. et sp. nov., Plioperdix hungarica (Janossy, 1991), as well as another form, similar in size to Mioryaba magyarica, but having a primitive structure for the tarsometatarsus and carpometacarpus.