Talk:Ankylosauridae
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[edit] New phylogeny of Ankylosauridae
A new cladistic analysis by Hill et. al. (2003) shows Polacanthidae to be paraphyletic, with Gargoyleosaurus, Gastonia, Hoplitosaurus, Hylaeosaurus, Mymmorapelta, and Polacanthus placed in different steps between one another. It also places Minmi within Ankylosauridae, resolving the position of Minmi itself. The phylogeny of Ankylosauridae after Hill et. al. (2003) is shown here:
Ankylosauridae
|--Gargoyleosaurus
`--+--Gastonia
`--+--Gobisaurus
`--+--Minmi
`--+--o Pinacosaurus
`--+--Talarurus
`--+--o Shamosaurinae
| |--Shamosaurus
| `--Tsagantegia
`--o Ankylosaurinae
|--+--Tarchia
| `--Saichania
|--Tianzhenosaurus
|--Nodocephalosaurus
|--Shanxia
|--Ankylosaurus
`--Euoplocephalus
The ankylosaurid taxa not included in the cladistic analysis are Acanthopholis, Aletopelta, Amtosaurus, Bissektipelta, Cedarpelta, Crichtonsaurus, Glyptodontopelta, Hoplitosaurus, Hylaeosaurus, Maleevus, Mymoorapelta, Polacanthus, and Sauroplites.
This paper not only recognizes the validity of Shanxia and Tianzhenosaurus, but it also proves that Polacanthidae is an artificial, paraphyletic assemblage and should be abandoned.
Hill, R. V., Witmer, L. M. & Norell, M. A., 2003: A New Specimen of Pinacosaurus grangeri (Dinosauria: Ornithischia) from the Late Cretaceous of Mongolia: Ontogeny and Phylogeny of Ankylosaurs. American Museum Novitates: 3395, pp. 1-29.
Therefore, add Minmi to the Ankylosauridae and revise the relations of ankylosaurid genera by deleting Polacanthidae. The paper mentioned above once again corroborates the monophyly of an nodosaurid-ankylosaurid dichotomy. —The preceding unsigned comment was added by 72.194.116.63 (talk) 01:32, 24 December 2006 (UTC).
- How exactly is it supposed to prove there is no Polacanthidae or Polacanthinae if it doesn't include Hylaeosaurus, Mymoorapelta, Hoplitosaurus, or, perhaps most importantly, Polacanthus? J. Spencer 16:11, 26 December 2006 (UTC)
- Yes, by definition Polocanthidae/inae must include Polacanthus. Interpreting a study that doesn't include that genus in this way is original research (original speculation, actually), unless the author of that paper actually discusses Polacanthus or polacanthidae. Dinoguy2 18:54, 26 December 2006 (UTC)
