[dinosaur] Evolution of modern avian digestive system + presbyornithid eggs and bones from Eocene of Africa

Ben Creisler
[email protected]

New papers about fossil birds:

Jingmai K. O'Connor &  Zhonghe Zhou (2019)
The evolution of the modern avian digestive system: insights from paravian
fossils from the Yanliao and Jehol biotas.
Palaeontology (advance online publication)
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1111_pala.12453&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=KovtaAPHhONHi5J2XqD3g79BYSZZnTQeFQCo2LOrm-o&s=oocMDF8lCXlehAemSxwfhOGBSBXOGTO3oEB9DaUJ1yw&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__onlinelibrary.wiley.com_doi_full_10.1111_pala.12453&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=KovtaAPHhONHi5J2XqD3g79BYSZZnTQeFQCo2LOrm-o&s=ESwNt5IPSyQ_UVaH-H31WhCWWiqbBd2rJ2B2zbmalq8&e= 

Data for this study (lists of all non‐avian paravian specimens and all
stem‐birds preserving ingested remains) are available in the Dryad Digital
Repository: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.5061_dryad.7kj764d&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=KovtaAPHhONHi5J2XqD3g79BYSZZnTQeFQCo2LOrm-o&s=v6vPBKV52-mxcbRgMtkFYQz3rVPb-FFb-olaZyOg1R0&e= 



The avian digestive system, like other aspects of avian biology, is highly
modified relative to other reptiles. Together these modifications have
imparted the great success of Neornithes, the most diverse clade of
amniotes alive today. It is important to understand when and how aspects of
the modern avian digestive system evolved among neornithine ancestors in
order to elucidate the evolutionary success of this important clade and to
understand the biology of stem birds and their closest dinosaurian
relatives: Mesozoic Paraves. Although direct preservation of the soft
tissue of the digestive system has not yet been reported, ingested remains
and their anatomical location preserved in articulated fossils hint at the
structure of the digestive system and its abilities. Almost all data
concerning direct evidence of diet in Paraves comes from either the Upper
Jurassic Yanliao Biota or the Lower Cretaceous Jehol Biota, both of which
are known from deposits in north‐eastern China. Here, the sum of the data
gleaned from the thousands of exceptionally well‐preserved fossils of
paravians is interpreted with regards to the structure and evolution of the
highly modified avian digestive system and feeding apparatus. This
information suggests intrinsic differences between closely related stem
lineages implying either strong homoplasy or that diet in each lineage of
non‐ornithuromorph birds was highly specialized. Regardless, modern
digestive capabilities appear to be limited to the Ornithuromorpha,
although the complete set of derived feeding related characters is
restricted to the Neornithes.


====

Géraldine Garcia, Cécile Mourer-Chauviré, Mohammed Adaci, Mustapha
Bensalah, Fateh Mebrouk, Xavier Valentin, M'hammed Mahboubi &
RodolpheTabuce (2019)
First discovery of avian egg and bone remains (Presbyornithidae) from the
Gour Lazib (Eocene, Algeria).
Journal of African Earth Sciences (advance online publication)
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1016_j.jafrearsci.2019.103666&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=KovtaAPHhONHi5J2XqD3g79BYSZZnTQeFQCo2LOrm-o&s=K7PrDLZOrsQt4wvl31tUgiSTWWeG8X7p3zEhp93f8pg&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.sciencedirect.com_science_article_pii_S1464343X19303218&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=KovtaAPHhONHi5J2XqD3g79BYSZZnTQeFQCo2LOrm-o&s=Yzc7gPnDQGmWgc4qOhccy35MS0nSbN0eSs_L7wapOQw&e= 

Highlights

Numerous avian eggshells and one well-preserved small ovoid-shaped egg
(32 × 28 mm) were collected from three localities in the Gour Lazib area
(HGL10, HGL51 and HGL62), western Algeria from the Glib Zegdou Formation
dated from the late early or early middle Eocene.
This material was associated with a rich vertebrate fauna. The study of the
eggshells using microscopies (PLM and SEM) led to attribute them to
neognathous birds.
They are characterized by a thin shell (less than 0.5 mm thick) with a
prismatic trilaminate microstructure.
The occurrence of an avian carpometacarpus belonging to the
Presbyornithidae from HGL50, which is located one meter below the HGL 51
level, suggests that the egg remains may be referred to this bird family,
which is so far unknown in the Palaeogene of the Afro-Arabian continent.


Abstract

Numerous avian eggshells and one well-preserved small ovoid-shaped egg
(32 × 28 mm) were collected from three localities in the Gour Lazib area
(HGL10, HGL51 and HGL62), western Algeria from the Glib Zegdou Formation
dated from the late early or early middle Eocene. This material was
associated with a rich vertebrate fauna. The study of the eggshells using
microscopies (PLM and SEM) led to attribute them to neognathous birds. They
are characterized by a thin shell (less than 0.5 mm thick) with a prismatic
trilaminate microstructure. The occurrence of an avian carpometacarpus
belonging to the Presbyornithidae from HGL50, which is located one meter
below the HGL 51 level, suggests that the egg remains may be referred to
this bird family, which is so far unknown in the Palaeogene of the
Afro-Arabian continent.



<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.avg.com_email-2Dsignature-3Futm-5Fmedium-3Demail-26utm-5Fsource-3Dlink-26utm-5Fcampaign-3Dsig-2Demail-26utm-5Fcontent-3Dwebmail&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=KovtaAPHhONHi5J2XqD3g79BYSZZnTQeFQCo2LOrm-o&s=RK2BI9e3_PYd8p9RN4umJ5Lkw4POCME-u_RDDKEZqnQ&e= >
Virus-free.
www.avg.com
<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.avg.com_email-2Dsignature-3Futm-5Fmedium-3Demail-26utm-5Fsource-3Dlink-26utm-5Fcampaign-3Dsig-2Demail-26utm-5Fcontent-3Dwebmail&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=KovtaAPHhONHi5J2XqD3g79BYSZZnTQeFQCo2LOrm-o&s=RK2BI9e3_PYd8p9RN4umJ5Lkw4POCME-u_RDDKEZqnQ&e= >
<#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>