Oviraptorosauria

   Oviraptorosauria here includes the oviraptorids, caenagnathids, and avimimids.  Oviraptorids and caenagnathids were grossly similar, although neither group is exhaustively known yet, given that for oviraptorids numerous taxa are just now being discovered and described, and no complete postcranium is known for caenagnathids (although wait a bit on that).  Both groups are composed of smallish, gracile, swift, dentally-challenged theropods with robust arms and unknown diets that could have been anything from vegetation to eggs to meat.  Avimimids were even smaller and swifter, and somewhat strange in their anatomy.  Indeterminate oviraptorosaurian remains include vertebrae from the Morrison Formation; those from the ?early Maastrichtian of Argentina have turned out to be noasaurid.  Interestingly, North America seems to be rich in caenagnathids and poor in oviraptorids, while the opposite is true of central Asia.
      
<--Oviraptorosauria
      |--+--Caudipteryx
      |    `--+--Elmisauridae
      |         |     `--Chirostenotes
      |         `--Oviraptoridae
      |              |--Oviraptorinae
      |              |    |--Citipati
      |              |    `--Rinchenia
      |              `--Ingeniinae
      |                   |--"Ingenia"
      |                   `--+--Conchoraptor
      |                        `--Khaan   
      `--Avimimidae
           `--Avimimus
    
Oviraptorosauria:  The three taxa here are close to the ancestry of the oviraptorids and caenagnathids.

Taxon or Taxa: Time\Place: Comments:
Caudipteryx:
Ji Q., Currie, Norell, and Ji S., 1998		 C. zoui (type) Ji. Q., Currie, Norell, and Ji. S., 1998 mid Barremian-early Aptian (EK) of China Based on material originally referred to Protarchaeopteryx, Caudipteryx is distinguished by teeth, arm length, and feather assortment.  It is nearly unique among classic theropods in that it is known to have had a gizzard full of stones to aid digestion.  Since both sauropodomorphs and birds are known to have had such gizzards, it is probable other theropods had them too.  Besides stomach stones, it had small conical teeth.  Caudipteryx gets its name from its long tail feathers. 
C. dongi is based on an articulated skeleton lacking the head, neck, and shoulders.
C. dongi Zhou and Wang, 2000

Oviraptorosauria i.s.:

Taxon or Taxa: Time\Place: Comments:
Caenagnathasia martinsoni Currie, Godfrey, and Nessov, 1993 late Turonian (LK) of Uzbekistan This animal is known from tiny, toothless dentaries (unfortunately, they now seem to be misplaced).
Caenagnathus: Sternberg, 1940 C. collinsi  (type) Sternberg, 1940 late middle Campanian (LK) of Alberta This taxon is based on toothless jaws and may be the same as Chirostenotes, or its own distinct genus, or one species may be the same as Chirostenotes and not the other.
C. sternbergi Cracraft, 1971 
Microvenator celer Ostrom, 1970 late Aptian-early Albian (EK) of Montana Microvenator is based on a partial postcranial skeleton discovered in the 1930s that was originally associated with large teeth.  Thinking these teeth belonged to the skeleton, Barnum Brown informally named the specimen "Megadontosaurus".  The teeth later turned out to belong to a larger theropod, Deinonychus, and the skeleton, named Microvenator, is now known to belong to a small basal relative of the oviraptorids.
Nomingia gobiensis Barsbold, Osmolska, Watabe, Currie, and Tsogtbaatar, 2000 early Maastrichtian (LK) of Mongolia This new oviraptorosaurian, originally known informally as "Nomingis brevicauda", is the first classic dinosaur known to have possessed a pygostyle (the verts of the tail fuse together), or something like one.  It may be a fairly basal member of the clade, perhaps close to the caenagnathids.  Remains include 13 presacrals, 5 sacrals, 24 caudals in order, pelvis, and partial hindlimbs.
?"Thecospondylus" daviesi (N.D.) Seeley, 1888 Barremian (EK) of England Also known as Thecocoelurus, this taxon, based on a cervical, does not pertain to the much larger Thecospondylus, but instead appears to be either an oviraptorosaurian, possibly related to the caenagnathids.  It was rather large, on the order of 7 meters long.

Elmisauridae:  The elmisaurids (also called caenagnathids, at least until Caenagnathus started giving signs that it was something else) are all closely related animals, with a gracile body and arctometatarsalian metatarsals.  They are also toothless, as far as we know.  They may just be oviraptorids with bad press.
    There is a large unnamed crested elmisaurid of Lancian age from South Dakota, known from excellent skeletons.  

Taxon or Taxa: Time\Place: Comments:
Chirostenotes pergracilis Gilmore, 1924 (including Macrophalangia canadensis Gilmore, 1932) late middle Campanian-early Maastrichtian (LK) of Alberta Based on some hands, C. pergracilis was long suspected of being the same as Macrophalangia, based on a foot, and Caenagnathus, based on jaws.  Skeletal remains found in the 1980s and '90s have shown the former to be true, but the latter, such a common suggestion in the '90s and early '00s, may not be correct.  Indeed, it may be that Caenagnathus is a fairly basal oviraptorosaurian, and Chirostenotes and allies true oviraptorids.  It has been suggested its second toe was capable of some hyperextension.
Research on the hands, which have unusually elongate second fingers, suggests that they were best suited for probing into narrow spaces with the second finger and for hooking.

Caenagnathidae i.s.:

Taxon or Taxa: Time\Place: Comments:
Elmisaurus: Osmolska, 1981 E. rarus (type) Osmolska, 1981 early Maastrichtian (LK) of Mongolia This taxon is closely related to Chirostenotes pergracilis and is based on hands and feet found in Mongolia.
E. elegans (Parks, 1933 [originally Ornithomimus]) late middle Campanian (LK) of Alberta and Montana Once a species of Ornithomimus, this species has found a home as an elmisaurid.  It could be referable to Chirostenotes.  New remains suggest it could have attained a size like that of Struthiomimus, around 4 meters long.
Hagryphus giganteus Zanno and Sampson, 2005 late Campanian (LK) of Utah The first unique named dinosaur from the newly-discovered Kaiparowits Formation fauna, Hagryphus is based mostly on a large left hand, with partial metatarsals, toes, and partial radius as well.  The specimen indicates an individual 30-40% larger than traditional Chirostenotes (although keep an eye out for that one).

Oviraptoridae i.s.: The oviraptorids can be quickly told from elmisaurids because they lack the arctometatarsalian condition of the elmisaurids.  Some have bizarre headgear.  All have bizarrely-constructed jaws, which are short and deep, that resemble little else among the classic dinosaurs.  An oviraptorid-like sacrum (fused hip verts) is known from the Albian (EK) of Brazil, possibly pushing back the age of the family.  Oviraptorid relationships are not very clear at this time; new research may indicate three subfamilies: Ingeniinae, Conchoraptorinae, and Oviraptorinae.  

Taxon or Taxa: Time\Place: Comments:
Gigantoraptor erlianensis Xu X., Tan Q., Wang J., Zhao X., and Tan L., 2007 early Maastrichtian (LK) of China From the Iren Dabashu Formation comes this albertosaur-scale basal oviraptorid.  The limbs, most of the girdles and the vertebrae after the neck, and the lower jaw are known, showing it to have had gracile long legs and large hands; despite all its size, it was quite "birdy".  It grew faster than tyrannosaurs and was 11 when it died.
Heyuannia huangi Lu, 2002 ?Maastrichtian (LK) of China Known from multiple remains from at least five individuals, this animal inspired some interesting press in dinosaur paleo circles a while back when it was suggested that reproductive organs were preserved with one individual.  It seems to be rather large for an oviraptorid, and the type is an excellent partially-articulated skeleton with a partial skull.
Shixinggia oblita Lü J. and Zhang, 2005 LK of China This new oviraptorid from southern China is based on remains collected in 1995, at least including the pelvis, femur and tibia (it has some odd openings in the latter).  More information will come as I get it.

Oviraptorinae:  

Taxon or Taxa: Time\Place: Comments:
Citipati osmolskae Clark, Norell, and Barsbold, 2001 late Campanian (LK) of Mongolia Citipati is another new oviraptorid based on good remains, a skeleton and skull; remains from two other individuals are known.
Possibly referable to this genus is specimen GI (SPS) 100/42, an excellent specimen (known for its crested skull) previously referred to Oviraptor, and the subject of most current restorations of "Oviraptor", including those in Gregory Paul's Predatory Dinosaurs of the World. 
Rinchenia mongoliensis Barsbold, 1997 (originally Oviraptor mongoliensis Barsbold, 1986) early Maastrichtian (LK) of Mongolia Based on a former species of Oviraptor, this large taxon possesses the tallest head crest of any oviraptorid.  It is not named by Barsbold for himself, but for his father.

Oviraptorinae i.s.:

Taxon or Taxa: Time\Place: Comments:
Nemegtomaia barsboldi Lü, Tomida, Azuma, Dong, and Lee, 2005 (originally Nemegtia Lü, Tomida, Azuma, Dong, and Lee, 2004) early Maastrichtian (LK) of Mongolia Described as closest to Citipati osmolskae, this genus is based on at least a skull with a prominent crest that has a nearly vertical rostral margin which is at about a 90-degree angle to the dorsal margin of the skull (this confuses me a bit; if I had to guess, this refers to the skull roof, as otherwise they would have said crest again.  However, this is somewhat self-evident, because a subvertical anterior margin has to be defined as such against some sort of reference).  As you might guess from the name, it comes from the Nemegt Formation.
Out of nowhere, it turned out that Nemegtia had already been used for an ostracod (a crustacean that wants to be a clam), hence the new name.
Oviraptor philoceratops Osborn, 1924 late Campanian (LK) of Mongolia Possessor of one of the most unusual skulls in all of dinosaurdom, Oviraptor also was one of the first dinosaurs that a clavicle was known for.  It got its distinctive species name because the type specimen was found over a nest of eggs, and it was assumed these eggs belong to Protoceratops.  It was later discovered such eggs were actually from oviraptorids, and that oviraptorids seemed to have protected their eggs by laying over them in a "brooding" position.  Some of these nests have skulls from very young troodontids in them, suggesting either the parent oviraptorids snatched them from troodontid nests and fed them to their young, or some troodontids were parasitic nesters, like modern cowbirds.  Among other unusual qualities, the arm and claws of Oviraptor are amazingly large, robust and similar to those of dromaeosaurids.  
Earlier, the size and extent of Oviraptor's crest was uncertain, and many restorations gave it either no crest or a sort of horn at the end of the snout.  Despite the removal of GI (SPS) 100/42 (see Citipati), the skull is still quite distinctive, with an odd crest on the midline that may get taller toward the rear of the skull.  Only the type skeleton can be safely assigned here at this point, though.  

Ingeniinae:

Taxon or Taxa: Time\Place: Comments:
"Ingenia" yanshini Barsbold, 1981 ?mid Campanian-early Maastrichtian (LK) of Mongolia The most unusual feature of this animal is its hands.  It has three clawed fingers, but unlike almost all other theropods, the digits are approximately the same length, with the first as longest, another unique feature.  It was weakly crested, with a low triangle on the snout end.
Recently, it was discovered that Ingenia was preoccupied by a nematode (Gerlach, 1957); a replacement name is in the pipeline, but has not been revealed yet.  Also, the urban legend that it was named after InGen from Jurassic Park, or has something to do with it, is completely false.
Conchoraptor gracilis Barsbold, 1986 ?mid Campanian (LK) of Mongolia This small, weakly crested taxon got its name through the belief it ate shellfish.
Khaan mckennai Clark, Norell, and Barsbold, 2001 late Campanian (LK) of Mongolia One of the smaller known oviraptorids, this recently-named and unspecialized taxon may be closest to Conchoraptor.  It is based on most of a skeleton and skull, with the mostly complete remains of three individuals known.

Avimimidae:  The avimimids so far known are small, gracile dinosaurs built for running.

Taxon or Taxa: Time\Place: Comments:
Avimimus portentosus Kurzanov, 1981 late Campanian (LK) of Mongolia, early Maastrichtian (LK) of China? One of the great enigmas to have surfaced in the last quarter century of dinosaur paleo, Avimimus has features that could be ascribed to sauropods, hadrosaurids, basal theropods, oviraptorids, birds, and ornithomimids.  It is a small, lightly-built theropod with a short, tall skull with small premaxillary teeth and amazingly birdlike features (including fused wrist and hand bones forming a carpometacarpus).  Sometimes considered a chimera, recent remains indicate it is not.  Possible attachments for feathers have been found on an ulna.  Foot remains assigned to Avimimus sp. have been found in the Judith River Formation, suggesting a North American branch.

Avimimdae i.s.:

Taxon or Taxa: Time\Place: Comments:
?Kakuru kujani Molnar and Pledge, 1980 Aptian (EK) of Australia Based on a partial opalizied tibia (sold at auction, but now rediscovered), this species resembles Avimimus in its tibia's slenderness, but also bears some resemblance to abelisauroids.

 

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