My Phylogeny: Now Slowly Comes Science

["David Marjanovic" <david.marjanovic@gmx.at>]

In June there was a thread "Coelurus a maniraptoran?", in which I placed my
hypothesis about the phylogeny of Maniraptoriformes and its surroundings. I
included various characters like "longer legs" and "shorter tail". HP Mickey
Mortimer urged that I quantify this. Now at last I have measured various
skeletal drawings for the trunk length : leg length : tail length ratios.
        Here I present the results. Unfortunately I don't have a good idea
how to standardize them into real ratios because sometimes the apomorphy is
a shortening of the trunk, sometimes a lengthening or shortening of the legs
and/or tail.

Trunk length = from the cranial end of dorsal vertebra 1 to above the
acetabulum
Leg length = from the dorsal end of the femur to the distal end of the
longest metatarsal (nearly always III)
Tail lengh = from above the acetabulum to the end
In cm as directly measured from the drawings along all curves, error range
up to +- 1 mm.

>From PDW (nearly all except *Torvosaurus* standardized to 1.3 cm femur
length, therefore comparable to one another)

taxon    trunk length    leg length    tail length
Lagosuchus    3.1    4.7    9
Lewisuchus    3.1    4.1    ?
Stauriko.    2.6    4    8.7
Herrera.    2.8    3.8    7.8
Coelophysis bauri
    gracile    3    3.6    9.2
    robust    3.8    3.6    10.5
Syntarsus rh.    3    3.7    7.2
Liliensternus    3.2    3.2    9.4
Dilopho.    3.1    3.2    8.3
Elaphro.    3.8    3.8    8.5
Cerato.    3.2    3.1    6.9
Baryonyx    2.8    3.2    7.1
Torvo.    3.8    3.9    9.2
Eustreptospondylus/Magnosaurus
    subadult    2.8    3.4    6.8
Piatnitzky.    2.5    3.3    ?
Yangchuan.    2.6    3.1    6.9
Allosaurus
    fragilis    2.5    3.1    7.5
    atrox    2.3    3    7.1
Compsognathus    3.4    4.3    10.9
Ornitholestes    2.3    3    8.4
Archaeopteryx
    subadult    2.5    4.1    4.8
    juvenile    2.3    4.4    5.1
Deinonychus
    gracile    2.4    3.6    9
    robust    2.4    3.4    8.2
Velociraptor    2.4    3.3    8.6
?Gorgosaurus    2.3    3.5    6.2
    juvenile    2.3    3.7    6.3
Daspleto.    2.4    3.3    6.8
Tyranno.
    bataar    2.4    3.2    6.1
        juv.    2.5    3.5    6
    rex    2.4    3.4    5.8
Struthio.    2.5    3.8    6.5
Dromiceio.    2.5    4.1    5.4
Gallimimus 2.9    3.9    6.1
    juv.    2.6    3.9    5.2
Troodon    > 2.3    4.1    < 8.3
    (fragmentary, reconstructed after dromaeosaurs)
Nanshiung.    3    3.1    5?
Oviraptor    2.4    3.7    ~5?
    (but see below)

>From its description (the femurs in the photos happen to be 1.3 cm long!)
Khaan    2.5    3.9    4.5

>From Dinosaurs: The Encyclopedia
Carcharo.    2.4    2.7    6.3
Alxasaurus    6.3    6.8    ~8?
Dromiceio.    3.8    6.4    8.6

>From its description:
Mononykus    2.4    5.9    6.4

Measured off the curved screen (Dinosauricon):
Sinornitho.    4.5    7.8    10
Yandang.    6.3    11.3    ?9 -- <12.3
Patagopteryx    >6    >11.5    ?
Gastornis    ?4    ?7.5    ?3.5

>From Dinosaurs of the Isle of Wight:
Eotyrannus    2.3    4.2    5.9

>From the SciAm Book of Dinosaurs:
Oviraptor by HP Tracy Ford (very *Caudipteryx*-like tail with only 21
vertebrae ~:-| )
    2.8    4.2    4.7
Confuciusornis (millimeters, measured through 4x magnifying glass)
    2.5    4    2
Sinornithoides    0.6    1.4    1.9
Caudipteryx    2.6    5.1    2.6
Columba    1    2    0.8

Summary: Ceratosaurs (whether paraphyletic or not) have long trunks and
short legs; tetanurans tend to have trunk lengths under 3 in PDW;
tyrannosaurs have longer legs and shorter tails than allosaurs; even though
ornithomimosaurs and troodontids have quite long legs, those of
*Archaeopteryx*, oviraptorosaurs, *Avimimus* and Metornithes are often
longer; *Archaeopteryx*, "enigmosaurs", *Yandangornis* and Metornithes have
very short tails. Small size and juvenile age mean shorter trunks, longer
legs and shorter tails. Basal Dinosauriformes and *Compsognathus* have legs
as long as in oviraptorosaurs, but much longer tails. *Caudipteryx* has damn
long legs and an incredibly short tail. %*)

=> The proportions of "enigmosaurs" and birds are indeed similar, probably
similar enough to be synapomorphic. *Archaeopteryx* must be regarded as
convergence or perhaps symplesiomorphy...