Schlagwort-Archive: USA

Nahmavis grandei Musser & Clarke

Endlich, endlich beschrieben!

Das dazugehörige Fossil ist schon seit etlichen Jahren bekannt und wurde ursprünglich als Angehöriger der ausgestorbenen Familie Salmilidae aus der Ordnung der Seriemaartigen (Cariamaformes) betrachtet.

Des Weiteren konnte man oft lesen, dass es sich um einen flugunfähigen Vogel mit winzigen Stummelflügeln gehandelt haben muss, schließlich kann man diese Flügelchen ja im Foto ganz gut erkennen … nun, nein, kann man eben nicht, was man hier sieht sind einfach nur etwas ‚unglücklich‘ gewachsene Federn; schaut man genau hin findet sich aber nicht die Spur irgendeines Flügelknochens!

Tatsächlich sind die Vordergliedmaßen des Tieres nach dem Tod bzw. während der Verwesung vollständig abhanden gekommen; sämtliche noch vorhandenen restlichen Teile weisen auf einen normal flugfähigen Vogel hin, er wird also zu Lebzeiten ganz normal ausgebildete Flügel besessen haben..

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Nahmavis grandei, so heißt der Vogel nun, ist ein sehr ursprünglicher Vertreter der Regenpfeiferfamilie (Charadriiformes).

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Referenzen:

[1] Lance Grande: The Lost World of Fossil Lake: Snapshots from Deep Time. University of Chicago Press 2013  
[2] Grace Musser; Julia A. Clarke: An exceptionally preserved specimen from the Green River Formation elucidates complex phenotypic evolution in Gruiformes and Charadriiformes. Frontiers in Ecology and Evolution. 8:559929. doi: 10.3389/fevo.2020.559929. 2020

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Foto aus: ‚Grace Musser; Julia A. Clarke: An exceptionally preserved specimen from the Green River Formation elucidates complex phenotypic evolution in Gruiformes and Charadriiformes. Frontiers in Ecology and Evolution. 8:559929. doi: 10.3389/fevo.2020.559929. 2020‘

(under creative commmons license (4.0))
http://creativecommons.org/licenses/by/4.0

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bearbeitet: 26.10.2020

SDSM 64281

SDSM 64281, also known as „Ornithurine C“ is mentioned in a study from 2011 that deals with the extinction of several bird clades at the end of the Cretaceous. [1]

This form is apparently known from at least one fragmented coracoid and comes from a bird that in life must have had a weight of about 3 kg. Unfortunatley the study fails to inform if this form is known from only the aforementioned single coracoid, and if not, if its remains were recovered only from the earliest Paleocene layers or if they were also recovered from the lates Cretaceous layers as it is the case with all other bird remains in the study.:

One of these species, Ornithurine C, is [also or only?] known from the Paleocene and therefore represents the only Maastrichtian bird known to cross the K–Pg boundary.“ 

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Apparently, this species is known from at least four coracoids or remains of such, and they are named as  „SDSM 64281A“, „SDSM 64281B“, „UCMP 175251“, and  „MOR 2918“ and most are indeed of Late Cretaceous age, but just not all of them.

According to the authors this species might be identical with a species that was named as Graculavus augustus Hope, a bird that apparently belongs to the Charadriiformes but was very much unlike any of the charadriiform birds living today, in life it may have appeared like some kind of giant stone-curlew aka. thick-knee. [2]

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References:

[1] Nicholas R. Longrich; Tim Tokaryk; Daniel J. Field: Mass extinction of birds at the Cretaceous-Paleogene (K-Pg) boundary. PNAS 108 (37) 15253-15257. 2011 
[2] Nicholas R. Longrich; Tim Tokaryk; Daniel J. Field: Mass extinction of birds at the Cretaceous-Paleogene (K-Pg) boundary. PNAS 108 (37) 15253-15257. 2011. Supplementary Information

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edited: 09.12.2019

FMNH PA789

This is a small bird from the Eocene of Wyoming, USA, it was only about 10 cm long and is so far known from a complete skeleton with most of the feathers preserved as well.

The bird is not yet described but is apparently currently under study, it may turn out to be related to Morsoravis sedilis Bertelli, Lindow, Dyke & Chiappe, and to belong into a new family, probably named the Morsorornithidae or alike, which then again are perhaps somehow related to the mousebird/parrot/songbird ‘orbit’.

The reconstruction shows it while somewhat stretching its left wing, it was ‘fun’ to draw all this wing feathers, and I probably will do that NEVER EVER AGAIN!!!   😉

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A little update here: 

This bird is now apparently included into the genus Morsoravis. [2]

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References:

[1] Lance Grande: The Lost World of Fossil Lake: Snapshots from Deep Time. University of Chicago Press 2013
[2] Daniel T. Ksepka; Lance Grande; Gerald Mayr: Oldest finch-beaked birds reveal parallel ecological radiations in the earliest evolution of passerines. Current Evolution 29(4): 657-663. 2019

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edited: 07.12.2019

Finch-like non-finches

Here we have the two species of finch-like passeriform birds that had been described at the beginning of this year, Eofringillirostrum boudreauxi and Eofringillirostrum parvulum, both from the Eocene, the first from North America, the second, smaller species from Europe.

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Eofringillirostrum boudreauxi Mayr, Ksepka & Grande

This is the larger of the two known species, reaching about 10 cm in length, it also is the older one, having lived in the Early Eocene about 52 Million years ago in what today is Wyoming, USA.

This is what I call a pre-sketch, or a working sketch, it’s just the very first step in reconstructing a fossil bird, in which this particular species is drawn in a simple side-view, usually smaller than life-size.

Eofringillirostrum parvulum Mayr, Ksepka & Grande

This bird may have reached a length of only about 9 cm, it lived in the Middle Eocene of what today is the State of Hesse in Germany.

I sketched it together with a reconstructed infructescence of Volkeria messelensis Smith, Collinson et al., a plant from the family Cyperaceae that was growing around the Messel lake, and whose seeds may indeed have been eaten by this presumably seed-eating bird.

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edited: 05-03.2019

Palaeotodus emryi Olson

This is just a doodle, or sketch of a Palaeotodus emryi, a rather large tody ancestor from the Early Oligocene of Wyoming, USA.    

This fossil tody was nearly 50% larger, and probably had a somewhat shorter bill and larger wings than the recent species.  

Today, todies are restricted to the Caribbean, where five species, which all more or less look the same, are found on Cuba, on Hispaniola as well as on Jamaica and Puerto Rico.  

It is very strange to see how little these birds have changed during the last 30 Ma. years of their known existence!

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edited: 22.05.2018

‘Neanis’ kistneri (Feduccia)

‘Neanis’ kistneri, the genus name written in quotation marks, because the bird does not belong into the genus Neanis, which otherwise includes a single species, Neanis schucherti Shufeldt, is a probable member of order Piciformes, and may be somewhat related to the family Galbulidae.

The species is known so far from a single, nearly complete skeleton, and, like so many Eocene birds, it was a dwarf.

This, of course, is just a sketch.