Friday, October 7, 2011

Waterfowl

WATERFOWL (Presbyornithid line)
  • Pterosaur (eg. Pterodactylidae/Ctenochasmatidae ) --->
  • Presbyornithid subgroup--> 
  • Modern Anseriformes (eg. Duck, Geese , Swan)
AND
  • Pterosaur (Ctenochasmatidae) Pterodaustro   --->
  • Presbyornithid subgroup--> 
  • Primitive bird, Palaelodidae (Phoenicopteriformes)  --> 
  • Flamingo (Phoenicopteriformes)

    http://en.wikipedia.org/wiki/Presbyornithidae
    Presbyornithidae were a family of waterbirds with an apparently global distribution that lived until the Earliest Oligocene, but are now extinct. Initially, they were believed to present a mix of characters shown by waterbirds,shorebirds and flamingos and were used to argue for an evolutionary relationship between these groups (Feduccia 1976), but they are now generally accepted to be "wading ducks", the sister taxon [actually the ancestor] of the Anatidae, and thus essentially modern waterbirds. They were generally long-legged, long-necked birds, standing around one meter high, with the body of a duck, feet similar to a wader but webbed, and a flat duck-like bill adapted for filter feeding.  Apparently, at least some species were very social birds that lived in large flocks and nested in colonies.

    As the "wading duck" moniker implies, they were waterfowl whose elongated legs enabled them to live a lifestyle similar to the "proto-flamingos" (e.g., Palaelodus) - which were not really ancestors of the modern flamingos, but a group that evolved in parallel with them and in fact seems to have taken over part of the presbyornithid's ecological niche after the latter became extinct. Thus, while probably somewhat capable of swimming, they would have preferred to strain the shallow waters of their habitat for food and were also able to snatch up insects and small crustaceans on dry land, just like some species of modern ducks, e.g., the Laysan Duck, hunt for brine flies.

    Presbyornithids
    Temporal range: Late Cretaceous? - Oligocene




    http://en.wikipedia.org/wiki/Presbyornis
    Presbyornis is an extinct genus of anseriform bird. It contains two unequivocally accepted species; the well-known P. pervetus and the much lesser-known P. isoni. P. pervetus was approximately the size and shape of a goose, but with longer legs; P. isoni, known from a few bones, was much larger, more than swan-sized. Other fossils, more doubtfully assigned to this genus, are also known.
    Judging from numerous fossil findings, Presbyornis is presumed to have lived in colonies around shallow lakes. Its broad, flat bill was used to filter food (small plants and animals) from the water, in the manner of today's dabbling ducks.[3]

    http://en.wikipedia.org/wiki/Galloanserae
    "Fowl were the first neognath lineages to evolve. From the limitedfossils that have to date been recovered, the conclusion that they were already widespread - the predominant group of modern birds - by end of the Cretaceous is generally accepted nowadays.Fossils such as Vegavis indicate that essentially modern waterfowl - albeit belonging to a nowadays extinctlineage - were contemporaries of the (non-avian)dinosaurs.

    Note: 
    It says "albeit belonging to a nowadays extinct lineage". It should say that the Vegavis developed into modern waterfowl. 

    http://en.wikipedia.org/wiki/Vegavis
    "Vegavis     is a genus of extinct bird that lived during the Late Cretaceous (Maastrichtian stage) of Antarctica, some 65 mya. It belonged to the clade Anseriformes.     Among modern birds,Vegavis is most closely related to ducks and geese (Anatidae), but it is not considered to be a direct ancestor of them." [However it possibly should be considered a direct ancestor of them].
    The discovery of the type species, Vegavis iaai, demonstrates that the major groups of bird alive today had already diversified in the Cretaceous. This supports the longstanding phylogenetic inferences of paleornithologists.[citation needed] It has been hailed as the first definitive physical proof that representatives of some of the groups of modern birds lived in theMesozoic.[1]"

     http://www.digimorph.org/specimens/Vegavis_iaai/nature03150.pdf
    and
    http://www.livescience.com/animals/050125_dino_chickens.html
    "We have more data than ever to propose at least the beginnings of the radiation of all living birds in the Cretaceous," Clarke says. "We now know that duck and chicken relatives coexisted with non-avian dinosaurs. This does not mean that today's chicken and duck species lived with non-avian dinosaurs, but that the evolutionary lineages leading to today's chicken and duck species did." (Julia A. Clarke1,2, Claudia P. Tambussi3, Jorge I. Noriega4,
    Gregory M. Erickson5,6,7 & Richard A. Ketcham8)


    FLAMINGOS
    http://en.wikipedia.org/wiki/Flamingo
    Relationships to the waterfowl were considered as well,[3] especially as flamingos and waterfowl are parasitized by feather lice of the genus Anaticola, which are otherwise exclusively found on ducks and geese.[4]


    Pterosaurs lasted till late Cretaceous
    Presbyornithids spanned from late Cretaceous? to Early Oligocene
    Palaelodidae spanned from early Oligocene to Middle Pleistocene
    Modern flamingos span from 30 mya to the present day


    http://www.flamingos-world.com/flamingo-evolution.html
    * There is evidence to indicate the Flamingo evolved at least 30 million years ago, perhaps longer. 


    "Our investigation of skeletal and ontogenetic variation in Pterodaustro gives insights into the
    developmental growth dynamics of this unusual ctenochasmatid pterodactyloid from early
    ontogeny through to adulthood and also pro vides information pertaining to histological variability within and between bones of individuals. This study also documents the presence of what appears to be medullary bone tissue within the medullary cavity of a large femur of Pterodaustro. This  suggests that,  like  birds,  reproductively  active female  pterosaurs  may have deposited a special bone tissue (medullary bone) to cope with  the demand of  calcium  during  eggshelling."
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