Ichthyornis

Name: Ichthyornis ‭(‬Fish bird‭)‬.
Phonetic: Ik-fee-or-niss.
Named By: Othniel Charles Marsh‭ ‬-‭ ‬1872.
Synonyms: Angelinornis,‭ ‬Colonosaurus,‭ ‬Graculavus anceps,‭ ‬Graculavus agilis,‭ ‬Ichthyornis agilis,‭ ‬Ichthyornis anceps,‭ ‬Ichthyornis antecessor,‭ ‬Ichthyornis tener,‭ ‬Ichthyornis victor,‭ ‬Ichthyornis validus,‭ ‬Plegadornis,‭
Classification: Chordata,‭ ‬Aves,‭ ‬Ornithurae,‭ ‬Carinatae,‭ ‬Ichthyornithes,‭ ‬Ichthyornithiformes,‭ ‬Ichthyornithidae.
Species: I.‭ ‬dispar‭ (‬type‭)‬.
Diet: Piscivore.
Size: About‭ ‬24‭ ‬centimetres long.‭ ‬Skeletal wingspan‭ ‬43‭ ‬centimetres long,‭ ‬in life would have been more with the addition of the feathers.
Known locations: Canada,‭ ‬including Alberta and Saskatchewan.‭ ‬USA,‭ ‬including Alabama,‭ ‬Kansas,‭ ‬New Mexico‭ & ‬Texas.
Time period: Cenomanian to Campanian of the Cretaceous.
Fossil representation: Multiple specimens including adult and juvenile individuals.

Ichthyornis‭ ‬-‭ ‬A brief history of the discovery and classification.
       Ever since its first description in‭ ‬1872,‭ ‬Ichthyornis has been one of the most important prehistoric birds known to us,‭ ‬but one that has been frequently mired in controversy.‭ ‬The very first specimen of Ichthyornis was first recovered in‭ ‬1870‭ ‬by Benjamin Franklin Mudge.‭ ‬Those who know their paleontological history will already know that at this time in North America the Bone Wars were in full swing.‭ ‬The Bone Wars were basically just the rivalry between two palaeontologists of the time named Edward Drinker Cope and Othniel Charles Marsh,‭ ‬and while they resulted in a great many discoveries,‭ ‬the period is usually held as an example of how not to conduct palaeontology.
       In‭ ‬1870‭ ‬Mudge‭ ‬was supplying his fossil discoveries to Cope but then things changed.‭ ‬Mudge had been a friend of Marsh in his younger years and Marsh decided to take advantage of this.‭ ‬This was always Marsh’s advantage over Cope in that he knew people in the right places to secure positions and work,‭ ‬and when he wrote to Mudge he asked him to send anything that he thought was significant to him instead of Cope.‭ ‬To sweeten the deal Marsh offered to do this for free and promised to give Mudge sole credit for the discovery.‭ ‬When Mudge received Marsh’s letter the first Ichthyornis specimen was already prepared for shipping to Cope‭; ‬it ended up going to Marsh instead.
       In their eagerness to outdo one another both Cope and Marsh missed several key things,‭ ‬and here Marsh failed to realise the importance of his bird specimen.‭ ‬Upon first study,‭ ‬Marsh thought that he had the remains of two creatures.‭ ‬The skeleton he thought belonged to a bird,‭ ‬no doubt about that,‭ ‬but there were long jaws had sharp teeth included with the pot cranial skeleton.‭ ‬At this time Marsh thought that these belonged to some reptile,‭ ‬possibly something like a small mosasaur.‭ ‬Marsh noted the unusual vertebrae of the bird skeleton and noted that they were concave‭ (‬curved inwards‭) ‬at both ends like those of fish.‭ ‬This yielded the rather simple name of Ichthyornis which means‭ ‘‬fish bird‭’‬.‭ ‬The jaws were attributed to their own genus,‭ ‬Colonosaurus mudgei.
       By early‭ ‬1873‭ ‬Marsh had realised that he had made a big mistake.‭ ‬Further preparation of the rock that held the bones resulted in further exposure of the remains that yielded a very startling discovery‭; ‬the toothed jaws were not those of a reptile,‭ ‬they belonged to the bird.‭ ‬Marsh immediately created the Odontornithes‭ (‬toothed birds‭) ‬and Ichthyornithes groups to classify his new discovery which was already sending shockwaves through the paleontological world.‭ ‬Ichthyornis became the first bird known to have had teeth within its jaws.‭ ‬For clarity,‭ ‬while Archaeopteryx was named in‭ ‬1861‭ ‬and was the first bird to be known from the Mesozoic age,‭ ‬the genus was not known to have had teeth as well until a specimen with a skull was described in‭ ‬1884.
       Ichthyornis was controversial.‭ ‬Charles Darwin’s Upon the Origin of Species had been first printed in‭ ‬1859‭ ‬and had upset a lot of people,‭ ‬particularly those with strong religious views who saw it as a challenge to the teachings of the Christian bible.‭ ‬Marsh’s specimen of Ichthyornis was a clear indicator that birds had a reptilian origin‭ (‬today we now know this to be the theropod dinosaurs‭)‬,‭ ‬and some people actually asked Marsh to hide the specimen away because it was such strong‭ ‬ proof of evolution in action.
       Others were less kind and instead accused Marsh of making a deliberate attempt at a hoax,‭ ‬and these claims have been as recent as‭ ‬1967.‭ ‬As always however,‭ ‬time has allowed the truth to be determined without doubt.‭ ‬Ichthyornis is now known by many specimens‭; ‬in fact it is one of the best represented fossil birds currently known.‭ ‬Other toothed birds of varying degrees of primitiveness are now also known,‭ ‬including Hesperornis,‭ ‬a genus of toothed bird that was different but lived in the same time and locations as Ichthyornis.‭ ‬Darwin himself considered both Hesperornis and Ichthyornis to represent important links in our understanding of evolution.
       Due to the large number of fossil remains,‭ ‬Ichthyornis now has many synonyms accredited to it.‭ ‬Obviously Colonosaurus mudgei,‭ ‬the name given to just the jaws in‭ ‬1872‭ ‬is a synonym but so is Angelinornis and two species of Graculavus,‭ ‬G.‭ ‬anceps and G.‭ ‬agilis.‭ ‬Ichthyornis was one broken down into many species but today only the type species is universally considered as valid.‭ ‬Older species are either synonyms to the type species or have been moved to other genera.‭ ‬Remains from Uzbekistan once thought to belong to‭ ‬the genus‭ ‬were later named as Austinornis.

Ichthyornis‭ ‬-‭ ‬The bird.
       In the simplest terms,‭ ‬Ichthyornis was a sea bird that was probably very similar to modern gulls in terms of ecological niche.‭ ‬As already mentioned,‭ ‬remains from Uzbekistan are no longer thought to belong to the genus,‭ ‬so the distribution of Ichthyornis is now the central portion of North America.‭ ‬This indicates that Ichthyornis lived along the coastline of the old Western Interior Seaway.‭ ‬This was a shallow sea that submerged most of central North America during the late Cretaceous.
       By the time of Ichthyornis birds had become competent flyers.‭ ‬The wing structure of Ichthyornis is more or less the same as in modern bird forms meaning that the wings were capable of performing efficient flight strokes.‭ ‬The skeletal wingspan of Ichthyornis is about forty-three centimetres long,‭ ‬but in life this would have been extended by the presence of flight feathers.‭ ‬The exact size of the wing is still uncertain because the flight feathers are still unknown.
       The sternum of Ichthyornis also display a strongly developed keel-like growth that projects forward.‭ ‬This bone would have been the main attachment point for strong pectoral muscles that would have enabled repetitive flapping of the wings to keep the bird in the air.‭ ‬The addition of fused metacarpals in the wings and presence of a pygostyle also indicate that Ichthyornis could make finer flight controls while in the air than far more primitive forms earlier in the Cretaceous and Jurassic.‭ ‬These features would have allowed Ichthyornis to fly out over the open sea for extended periods as well as possibly exploit air currents over the water’s surface.
       Rather than being a single sheet of keratin,‭ ‬the beak of Ichthyornis was composed of several segments that formed a whole,‭ ‬the beak of the albatross would be a modern analogy to this.‭ ‬The teeth of Ichthyornis were laterally compressed‭ (‬flattened to the sides‭) ‬and the tips were recurved so that they pointed towards the rear of the mouth.‭ ‬A key note about the teeth is that they were only present in the middle portion of the mouth,‭ ‬the front portion is completely lacking.‭ ‬The teeth themselves likely facilitated prey capture of marine organisms such as late Cretaceous fish that swam too close to the surface.

Further reading
-‭ ‬Notice of a new reptile from the Cretaceous‭ ‬-‭ ‬Othniel Charles Marsh‭ ‬-‭ ‬1872.
-‭ ‬Notice of a new and remarkable fossil bird‭ ‬-‭ ‬Othniel Charles Marsh‭ ‬-‭ ‬1872b.
-‭ ‬On a new sub-class of fossil birds‭ (‬Odontornithes‭) ‬-‭ ‬Othniel Charles Marsh‭ ‬-‭ ‬1873.
-‭ ‬The jaws of the Cretaceous toothed birds,‭ ‬Ichthyornis and Hesperornis‭ ‬-‭ ‬J.‭ ‬T.‭ ‬Gregory‭ ‬-‭ ‬1952.
-‭ ‬Marsh was right:‭ ‬Ichthyornis had a beak‭ ‬-‭ ‬J.‭ ‬P.‭ ‬Lamb Jr‭ ‬-‭ ‬1997.
-‭ ‬Bone microstructure of the diving Hesperornis and the volant Ichthyornis from the Niobrara Chalk of western Kansas‭ ‬-‭ ‬A.‭ ‬Chinsamy,‭ ‬L.‭ ‬D.‭ ‬Martin‭ & ‬P.‭ ‬Dobson‭ ‬-1998.
-‭ ‬Vertebrate Biostratigraphy of the Smoky Hill Chalk‭ (‬Niobrara Formation‭) ‬and the Sharon Springs Member‭ (‬Pierre Shale‭) ‬-‭ ‬K.‭ ‬Carpenter‭ ‬-‭ ‬2003.
-‭ ‬Morphology,‭ ‬phylogenetic taxonomy,‭ ‬and systematics of Ichthyornis and Apatornis‭ (‬Avialae:‭ ‬Ornithurae‭) ‬-‭ ‬J.‭ ‬A.‭ ‬Clarke‭ ‬-‭ ‬2004.
-‭ ‬Ichthyornis sp.‭ (‬Aves:‭ ‬Ichthyornithiformes‭) ‬from the lower Turonian‭ (‬Upper Cretaceous‭) ‬of western Kansas‭ ‬-‭ ‬K.‭ ‬Shimada‭ & ‬M.‭ ‬V.‭ ‬Fernandes‭ ‬-‭ ‬2006.



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