FACTOID # 19: Cheap sloppy joes: Looking for reduced-price lunches for schoolchildren? Head for Oklahoma!
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Hesperornithes
iHesperornithes
Fossil range: Cretaceous
Hesperornis regalis skull
Hesperornis regalis skull
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Subclass: Hesperornithes
Fürbringer, 1888
Order: Hesperornithiformes
Sharpe 1899
Families

Enaliornithidae
Baptornithidae
Hesperornithidae The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i. ... This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ... Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Phyla Subregnum Parazoa Porifera Subregnum Eumetazoa Placozoa Orthonectida Rhombozoa Radiata (unranked) Ctenophora Cnidaria Bilateria (unranked) Acoelomorpha Myxozoa Superphylum Deuterostomia Chordata Hemichordata Echinodermata Chaetognatha Xenoturbellida Superphylum Ecdysozoa Kinorhyncha Loricifera Priapulida Nematoda Nematomorpha Onychophora Tardigrada Arthropoda Superphylum Platyzoa Platyhelminthes Gastrotricha Rotifera Acanthocephala Gnathostomulida Micrognathozoa Cycliophora Superphylum Lophotrochozoa Sipuncula Nemertea Phoronida Bryozoa Entoprocta... Typical Classes Subphylum Urochordata - Tunicates Ascidiacea Thaliacea Larvacea Subphylum Cephalochordata - Lancelets Subphylum Myxini - Hagfishes Subphylum Vertebrata - Vertebrates Petromyzontida - Lampreys Placodermi (extinct) Chondrichthyes - Cartilaginous fishes Acanthodii (extinct) Actinopterygii - Ray-finned fishes Actinistia - Coelacanths Dipnoi - Lungfishes Amphibia - Amphibians Reptilia - Reptiles Aves - Birds Mammalia - Mammals Chordates (phylum Chordata) include the vertebrates, together with... For other meanings of bird, see bird (disambiguation). ... Max Fürbringer (1846–1920) was a German anatomist. ... 1888 (MDCCCLXXXVIII) is a leap year starting on Sunday (click on link for calendar) of the Gregorian calendar or a leap year starting on Tuesday of the Julian calendar. ... Richard Bowdler Sharpe (November 22, 1847 - December 25, 1909) was an English zoologist. ... 1899 (MDCCCXCIX) was a common year starting on Sunday (see link for calendar). ... Binomial name Baptornis advenus Marsh, 1877 Baptornis (diving bird) is an extinct genus of primitive bird. ...

Synonyms

Odontornithes Marsh1873 (partim)
Odontolcae Marsh1875
Gaviomorphae Cracraft, 1982 (partim) In scientific nomenclature, synonyms are different scientific names used for a single taxon. ... Odontornithes is an obsolete taxonomic term proposed by O. C. Marsh for birds possessing teeth, notably the genera Hesperornis and Ichthyornis from the Cretaceous deposits of Kansas. ... Othniel Charles Marsh (October 29, 1831 - March 18, 1899) was one of the pre-eminent paleontologists of the 19th century, who discovered and named many fossils found in the American West. ... 1873 (MDCCCLXXIII) was a common year starting on Wednesday (see link for calendar). ... Othniel Charles Marsh (October 29, 1831 - March 18, 1899) was one of the pre-eminent paleontologists of the 19th century, who discovered and named many fossils found in the American West. ... 1875 (MDCCCLXXV) was a common year starting on Friday (see link for calendar). ... 1982 (MCMLXXXII) was a common year starting on Friday of the Gregorian calendar. ...

Hesperornithes are an extinct and highly specialized subclass of Cretaceous toothed birds. Hesperornithiform birds, apparently limited to former aquatic habitats in the Northern Hemisphere, include genera such as Hesperornis, Parahesperornis, Baptornis, Enaliornis, and probably Potamornis, all strong-swimming predatory waterbirds. Many, if not all species were completely flightless. The largest known hesperornithiform, described in 1999 and named Canadaga arctica, may have reached a maximum adult length of over 1.5 meters (five feet). The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i. ... Orders Many - see section below. ... In biology, a genus (plural genera) is a taxonomic grouping. ... 1999 (MCMXCIX) was a common year starting on Friday, and was designated the International Year of Older Persons by the United Nations. ...


Hesperornithiform birds were, strictly speaking, the only dinosaurs to colonize the oceans; the aquatic reptiles of their time, such as the ichthyosaurs and plesiosaurs, were not dinosaurs. Orders & Suborders Saurischia Sauropodomorpha Theropoda Ornithischia Thyreophora Ornithopoda Marginocephalia Dinosaurs were vertebrate animals that dominated the terrestrial ecosystem for over 160 million years, first appearing approximately 230 million years ago. ... Orders Procolophonia (extinct) Testudines Araeoscelidia (extinct) Avicephala (extinct) Younginiformes (extinct) Sauropterygia Ichthyosauria (extinct) Placodontia (extinct) Nothosauria (extinct) Plesiosauria (extinct) Sphenodontia Squamata Prolacertiformes (extinct) Archosauria Crurotarsi Order Aetosauria (extinct) Order Phytosauria(extinct) Order Rauisuchia (extinct) Order Crocodilia Ornithodira Pterosauria (extinct) Marasuchus (extinct) Dinosauria Order Saurischia Order Ornithischia(extinct) Reptiles are tetrapods... Taxonomy See text Ichthyosaurs (Greek for fish lizard - ιχθυς meaning fish and σαυρος meaning lizard) were giant marine reptiles that resembled fish and dolphins. ... Families Plesiosaurs (IPA ) (Greek: plesios, near to + sauros, lizard) were large, carnivorous aquatic reptiles. ...

Contents

Anatomy and ecology

Although some of the smaller species might have been able to fly, Hesperornis and Baptornis had only vestigial wings. Like living foot-propelled diving birds, the femur and metatarsus were short, whereas the tibia was long. The legs were also set far back on the body, as in loons, grebes or penguins. Hesperornithiformes must have been powerful swimmers and divers but extremely ungainly on the land, and probably spent little time ashore except to nest (indeed, it has been suggested that they did not incubate their eggs[citation needed]). Some researchers think that on land they had to slide on their bellies and push with their legs; the hip and knee joints were shaped such that these birds could not move them dorsoventrally, and in a resting position the feet projected sideways from the body, which would have prevented them from walking. The joints of the toes resemble those of grebes, suggesting that the foot bore a series of lobes rather than a single web. The dense bones of these birds decreased their buoyancy, making diving easier (Chinsamy et al. 1998). To meet Wikipedias quality standards, this article or section may require cleanup. ... Genera Podiceps Tachybaptus Podilymbus Aechmophorus Poliocephalus Rollandia Grebes are members of the Podicipediformes order, a widely distributed order of freshwater diving birds, some of which visit the sea when migrating and in winter. ... Modern Genera Aptenodytes Eudyptes Eudyptula Megadyptes Pygoscelis Spheniscus For extinct genera, see Systematics Penguins (order Sphenisciformes, family Spheniscidae) are an order of aquatic, flightless birds living exclusively in the Southern Hemisphere. ...


The beak was long, probably hooked at the tip, and bore a series of simple, sharp teeth which were set into a longitudinal groove. These and probably helped to seize fish, as does the serrated beak of mergansers today; unlike the reptilian teeth of other toothed birds, those of the Hesperornithes were unique (Gregory, 1952); given that teeth are induced by a rather simple genetic mechanism[citation needed], it is even possible that these birds re-evolved them and that the ancestors of the hesperornithids ancestors were toothless. A giant grouper at the Georgia Aquarium Fish are aquatic vertebrates that are typically cold-blooded; covered with scales, and equipped with two sets of paired fins and several unpaired fins. ... † For other related ducks, see also: Merginae Mergus is a genus of ducks in the seaduck subfamily Merginae. ...


Systematics and evolution

These birds were originally combined with Ichthyornis in the paraphyletic Odontornithes by Othniel Charles Marsh, in 1873. In 1875, they were separated as Odontolcae. The group was considered to be allied to loons and grebes (Cracraft, 1982[1]), or to the Paleognathae (based on a perceived similarity of the bony palate: Gingerich, 1973). These similarities, however, as the more recently determined fact that the osteons of their bones - at least in Hesperornis - were arranged in a pattern similar to that in Neognathae (Houde, 1987), are today considered to be due to convergent evolution. This article does not cite its references or sources. ... Paraphyletic - Wikipedia /**/ @import /skins-1. ... Othniel Charles Marsh (October 29, 1831 - March 18, 1899) was one of the pre-eminent paleontologists of the 19th century, who discovered and named many fossils found in the American West. ... This article does not cite its references or sources. ... The hard palate is a thin horizontal bony plate of the skull, otherwise known as the palatine process of the maxilla, located in the roof of the mouth. ... Osteons (cross section) Osteons (also called Haversian system in honor of Clopton Havers) are predominant structures found in some lamellar or compact bone. ... Orders Anseriformes, waterfowl Galliformes, fowl Gaviiformes, loons Podicipediformes, grebes Procellariiformes, albatrosses, petrels, and allies Sphenisciformes, penguins Pelecaniformes, pelicans and allies Ciconiiformes, storks and allies Phoenicopteriformes, flamingos Accipitriformes, eagles, hawks and allies Falconiformes, falcons Turniciformes, button-quail Gruiformes, cranes and allies Charadriiformes, plovers and allies Pteroclidiformes, sandgrouse Columbiformes, doves and pigeons... It has been suggested that Morphological convergence be merged into this article or section. ...


Currently, the hesperornithiform birds are recognized as a very specialized lineage that is not ancestral or otherwise closely related to the birds of today. Still, their relationship is close enough to make Hesperornis regalis is the first species of essentially moden bird discovered, and they possibly diverged from the ancestors of today's birds as late as the Earliest Cretaceous. On the other hand, given the great number of convergent traits already discovered in hesperornithforms, it is not inconceivable that they represent a wholly independent avian lineage.


The discovery that Gansus yumenensis, which lived some time before the main radiation of the Hesperornithiformes, was a primitive member of the Ornithurae - that is, birds which had developed the type of pygostyle that is also found in modern birds - suggests that the ancestors of the Hesperornithes - also Ornithurae - may have been birds generally similar to Gansus and living some 130-150 mya. Given the tendency of birds that have become flightless to increase in size markedly in just a few million years, the probability of the Hesperornithes deriving from an animal at least superficially similar and not too far related to Gansus is quite high. The new fossil material of that species should assist in determining the degree of synapomorphy of the Hesperornithes and other Ornithurae, which have until now been muddied by the strong autapomorphy of the former. Binomial name Gansus yumenensis Hou & Liu, 1984 Gansus is a genus of aquatic birds that lived during the Albian stage of the Early Cretaceous period (around 110 million years ago) in what is now Gansu province, western China. ... It has been suggested that this article or section be merged into bird skeleton. ... In astronomy, geology, and paleontology, mya is an acronym for million years ago and is used as a unit of time to denote length of time before the present. ... Shared characteristics that define a cladistic grouping. ... An autapomorphy in cladistics is a derived trait that is unique to a given taxon. ...


Loss and/or fusion of caudal vertebrae in pygostyle-like structures was a general trend in Cretaceous avian evolution, and a full pygostyle and associated structures may have evolved more than once to similar shapes. The fact that Gansus had non-pneumatized dense bones as the Hesperornithes, although it was not a specialized diver, is interesting to note. A diagram of a thoracic vertebra. ...


Similarly, the bone structure of Hesperornis indicates that as opposed to Enantiornithes and in line with other Ornithurae it showed rapid, uninterrupted growth to adult size (Chinsamy et al. 1998). The Enantiornithes, or opposite birds (because their foot bones are fused differently than in modern birds), are an extinct group of flying birds. ...


The earliest known hesperornithiform is the Early Cretaceous Enaliornis although these birds are somewhat tentatively assigned to this group because of the bad preservation of their remains; the majority of hesperornithiform taxa are known from the Late Cretaceous. Hesperornis has been found in Late Cretaceous marine chalks from Kansas and in marine shales from Canada. Small hesperornithiform bones are known from the freshwater deposits of the Late Cretaceous of the Judith River Group as well as the Hell Creek and Lance Formations. These birds were about the size of a cormorant or a loon. The Early Cretaceous (timestratigraphic name) or the Lower Cretaceous (logstratigraphic name), is the earlier of the two major divisions of the Cretaceous period. ... A taxon (plural taxa), or taxonomic unit, is a grouping of organisms (named or unnamed). ... Geography of the US in the late Cretaceous Late Cretaceous (also called the Upper Cretaceous) refers to the second half of the Cretaceous period, named after the famous white chalk cliffs of southern England, which date from this time. ... This article or section does not cite its references or sources. ... The Judith River Group is a group of geologic formations in western North America dating from the late Cretaceous and noted as a site for the extensive excavation of dinosaur fossils. ... The Hell Creek Formation is the division of Upper Cretaceous rocks in North America. ... The Lance Formation is a division of Late Cretaceous rocks in the western United States. ...


The following classification is a synthesis of Marsh (1880), Feduccia (1996), Tokaryk, Cumbaa & Storer (1997), and Galton & Martin (2002) (via Haaramo, 2005), as well as Clarke (2004) and Sereno (2005).

Hesperornis regalis reconstruction by Marsh. Though a popular depiction, the bird is now known to have been completely unable to assume such a posture. See above for correct position of the legs
Enlarge
Hesperornis regalis reconstruction by Marsh. Though a popular depiction, the bird is now known to have been completely unable to assume such a posture. See above for correct position of the legs
  • Class AVES
    • Subclass HESPERORNITHES
      • Order HESPERORNITHIFORMES
        • Basal and unresolved taxa
          • Genus Asiahesperornis (Late Cretaceous of Kazakhstan) - hesperornithid?
          • Genus Judinornis (Nemegt Late Cretaceous of S Mongolia)
          • Genus Potamornis (Lance Creek Late Cretaceous of Buck Creek, USA) - hesperornithid?
          • Genus Pasquiaornis
          • Hesperornithiformes gen. et sp. indet. (Late Cretaceous of Kushmurun, Kazakhstan)
          • Hesperornithiformes gen. et sp. indet. TMP 89.81.12 (Dinosaur Park Late Cretaceous of Iddesleigh, Canada)
        • Family Enaliornithidae
          • Genus Enaliornis (Early Cretaceous of Cambridge, England)
        • Family Baptornithidae
          • Genus Baptornis (Late Cretaceous of C North America)
        • Family Hesperornithidae
          • Genus Hesperornis (Late Cretaceous of C North America)
          • Genus Parahesperornis (Late Cretaceous of C North America)
          • Genus Coniornis
          • Genus Canadaga

Sometimes assigned to the Hesperornithes, but actual relationship unknown Image File history File links Hesperornis_Regalis_-_Project_Gutenberg_eText_16474. ... Image File history File links Hesperornis_Regalis_-_Project_Gutenberg_eText_16474. ... Othniel Charles Marsh (October 29, 1831 - March 18, 1899) was one of the pre-eminent paleontologists of the 19th century, who discovered and named many fossils found in the American West. ... Families Enaliornithidae Baptornithidae Hesperornithidae Synonyms Odontornithes Marsh, 1873 (partim) Odontolcae Marsh, 1875 Gaviomorphae Cracraft, 1982 (partim) Hesperornithes are an extinct and highly specialized subclass of Cretaceous toothed birds. ... For other meanings of bird, see bird (disambiguation). ... Binomial name Baptornis advenus Marsh, 1877 Baptornis (diving bird) is an extinct genus of primitive bird. ... Binomial name Baptornis advenus Marsh, 1877 Baptornis (diving bird) is an extinct genus of primitive bird. ... Families Hesperornithidae Hesperornithiformes are an extinct and highly specialized order of Cretaceous toothed birds. ...

  • Genus Neogaeornis
  • Genus Parascaniornis

References

  • Chinsamy, A.; Martin, Larry D. & Dobson, P. (1998): Bone microstructure of the diving Hesperornis and the volant Ichthyornis from the Niobrara Chalk of western Kansas. Cretaceous Research 19(2): 225-235. DOI:10.1006/cres.1997.0102 (HTML abstract)
  • Clarke, J. A. (2004): Morphology, Phylogenetic Taxonomy, and Systematics of Ichthyornis and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum of Natural History 286: 1-179 PDF fulltext
  • Cracraft, Joel (1982): Phylogenetic relationships and monophyly of loons, grebes, and hesperornithiform birds, with comments on the early history of birds. Systematic Zoology 31: 35-56. DOI:10.2307/2413412 (HTML abstract)
  • Feduccia, A. (1996): The origin and evolution of birds. Yale University Press, New Haven and London.
  • Fürbringer, M. (1888): Untersuchungen zur Morphologie und Systematik der Vögel (2 vols). Von Holkema, Amsterdam.
  • Galton, P. M. & Martin, L. D. (2002): Enaliornis, an Early Cretaceous Hesperornithiform Bird from England, with Comments on Other Hesperornithiformes. 317-338. In: Chiappe, L. M. & Witmer, L. M. (eds.): Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press, Berkeley, Los Angeles, London.
  • Gingerich, P. D. (1973): Skull of Hesperornis and the early evolution of birds. Nature 243: 70-73. DOI:10.1038/243070a0 (HTML abstract)
  • Gregory, Joseph T. (1952): The Jaws of the Cretaceous Toothed Birds, Ichthyornis and Hesperornis. Condor 54(2): 73-88. PDF fulltext
  • Haaramo, Mikko (2005): Mikko's Phylogeny Archive: †Hesperornithiformes. Version of 2005-11-15. Retrieved 2006-09-21.
  • Houde, Peter (1987): Histological Evidence for the Systematic Position of Hesperornis (Odontornithes: Hesperornithiformes). Auk 104(1): 125-129 PDF fulltext
  • Marsh, Othniel Charles (1880): Odontornithes, a Monograph on the Extinct Toothed Birds of North America. Government Printing Office, Washington DC.
  • Tokaryk, T. T.; Cumbaa, S. L. & Storer, J. E. (1997): Early Late Cretaceous birds from the Saskatchewan, Canada: The oldest diverse avifauna known from North America. Journal of Vertebrate Paleontology: 17(1): 172-176. HTML abstract

A digital object identifier (or DOI) is a permanent identifier (permalink) given to a World Wide Web file or other Internet document so that if its Internet address changes, users will be redirected to its new address. ... A digital object identifier (or DOI) is a permanent identifier (permalink) given to a World Wide Web file or other Internet document so that if its Internet address changes, users will be redirected to its new address. ... First title page, November 4, 1869 Nature is one of the oldest and most reputable scientific journals, first published on 4 November 1869. ... A digital object identifier (or DOI) is a permanent identifier (permalink) given to a World Wide Web file or other Internet document so that if its Internet address changes, users will be redirected to its new address. ... The Condor is the quarterly journal of the Cooper Ornithological Society. ... The Auk is a quarterly journal and the official publication of the American Ornithologists Union, having been continuously published by that body since 1884. ... The Society of Vertebrate Paleontology was founded in 1940 for individuals with an interest in vertebrate paleontology. ...

Footnotes

  1. ^ An interesting example of how to arrive at an essentially phenetic - and utterly incorrect - analysis in spite of using cladistic methods.

In biology, phenetics, also known as numerical taxonomy, is an attempt to classify organisms based on overall similarity, usually in morphology or other observable traits, regardless of their phylogeny or evolutionary relation. ... Greek clados = branch) or phylogenetic systematics is a branch of biology that determines the evolutionary relationships of living things based on derived similarities. ...

External links

  • Hesperornis regalis Marsh 1872 Toothed marine birds of the Late Cretaceous seas by Mike Everhart, Oceans of Kansas website. Retrieved 2006-09-16.

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m