Coelurosauria

    The second great division of Avetheropoda, Coelurosauria is beyond any doubt the most diverse group of theropods, even without factoring in birds.  There are giant superpredators (tyrannosaurids), toothless racers (ornithomimids), two kinds of sickle-clawed birdlike hunters (dromaeosaurids and troodontids), strange sloth-like herbivores with giant hand claws (therizinosaurians), little animals with an unknown diet and bizarre mandibles and sometimes head crests (oviraptorids and elmisaurids, on the same page), and some of the smallest known classic theropods (compsognathids).  They all tend to have relatively long arms, except for the tyrannosauroids which secondarily shortened them, probably for weight reduction, and the alvarezsaurids, who reduced their arms to powerful single-clawed stubs, possibly for digging.  All members of Coelurosauria may have been feathered or derived from ancestors who had that characteristic.
    Tyrannoraptora has been named for the combination of Tyrannosauroidea and Maniraptoriformes, which corresponds in membership to my old Maniraptoriformes, back when I had Arctometatarsalia.  An important historical development in Tyrannoraptora is the Tyrannosauroidea/Arctometatarsalia saga, wherein Tyrannosauroidea was introduced to Coelurosauria as a member of a larger grouping known as Arctometatarsalia, which also was to include ornithomimosaurians, elmisaurids, and troodontids.  The key character linking these diverse groups was the third metatarsal's relationship with the second and fourth mts.  In arctomets, the third metatarsal was pinched off at the top in front view.  Later, it became clear that most groups of "arctomets" had acquired this condition convergently; this category includes the elmisaurids, which are closely related to the oviraptorids, the ornithomimosaurians, and the troodontids, which had been classified in a group with the ornithomimosaurians because they shared similar swellings in a bone of the braincase (Bullatosauria, or "inflated lizards"), but now appear to be closer to the dromaeosaurids.  Tyrannosauroidea and Ornithomimosauria, or Ornithomimosauria and Alvarezsauridae, are about the only groups that people will occasionally still link as arctomets, but even these small versions of Arctometatarsalia are going by the wayside, as it becomes more and more evident that the arctomet was just a good anatomical idea that several different groups found at different times, or an idea present at the base of, say, Tyrannoraptora, that was further expanded upon or lost by the more derived groups (this second option seems better as we get more information on the basal members of those groups, something we didn't have before).
 
<--Coelurosauria
      |--Compsognathidae
      |    |--Huaxiagnathus
      |    `--+--?Sinosauropteryx
      |         `--+--Mirischia
      |              `--Compsognathus
      `--+--Nedcolbertia
           |--?Scipionyx
           `--+--"Ornitholestidae"
                |      |--Nqwebasaurus
                |      `--Ornitholestes
                `--Tyrannoraptora
                     |-->Tyrannosauroidea
                     `--+--Coelurus 
                          `--Maniraptoriformes
                               |-->Ornithomimosauria
                               `-->Maniraptora

Compsognathidae: Compsognathids are renowned as the smallest known adult classic dinosaurs, measuring somewhat over a meter in length fully grown in some cases (although their lofty status appears to be in doubt; see Microraptor).  Compsognathids were small, fleet theropods with very long tails and reduced arms.  Indeed, until the discovery of Sinosauropteryx's three clawed hands it was believed compsognathids had only two fingers per hand, a result of the ambiguous condition of the hands in Compsognathus specimens.  These animals were small game hunters, as shown by the discovery of mammal and lizard remains in the belly region of several specimens.
    Compsognathidae may be an artificial assemblage of a variety of small basal coelurosaurs, some of which may pertain to a true Compsognathidae, others to basal Tyrannosauroidea (it turns out that basal tyrannosauroids were not all that different from generalized basal coelurosaurs). 
    Material from the EK of Thailand may be referable to this family.

Compsognathidae i.s.:

Other Coelurosauria: A new basal coelurosaurian, based on two partial skeletons from the middle Turonian (LK) of New Mexico, is currently being described.  Also, a possible basal coelurosaurian femur is known from the EK Wealden Formation, and a 7-8 meter long form has been uncovered in the LK of Argentina, with partial skeleton and skull.  Basal coelurosaurians in general are a bit of a mess.  

Coelurosauria i.s.:

"Ornitholestidae": I'm reviving the name as a family of convenience for some basal coelurosaurians that seem to group together.

Tyrannoraptora:

Tyrannoraptora i.s.:  Two new theropods from the LJ of China have been uncovered; one, known from a partial skeleton, is troodontid-like, while the other, known from the caudal half of a skeleton, is ornithomimosaurian-like.