comment on this calibration
Heterodon + Farancia
Lineage (NCBI):
root
» Eukaryota
» Opisthokonta
» Metazoa
» Eumetazoa
» Bilateria
» Coelomata
» Deuterostomia
» Chordata
» Craniata <chordata>
» Vertebrata <Metazoa>
» Gnathostomata <vertebrate>
» Euteleostomi
» Sarcopterygii
» Tetrapoda
» Amniota
» Sauropsida
» Sauria
» Lepidosauria
» Scleroglossa
» Serpentes
» Colubroidea
» Colubridae
» Xenodontinae
| node name Heterodon + Farancia Look for this name in NCBI Wikipedia Animal Diversity Web | ||
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recommended citations http://palaeo-electronica.org/content/fc-9 Head et al. 2016 |
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node minimum age 12.08 Ma The minimum age is based on the Swallow Ash of the lowermost Ash Hollow Formation, which succeeds the Valentine Formation (Tedford et al., 2005). The Myers Farm fauna is coeval with the Valentine Formation based on mammalian faunal composition and is considered latest Barstovian (e.g., Janis et al., 1998; Bair, 2011). | ||
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node maximum age None specified | ||
| primary fossil used to date this node | ||
USNM 46504 | ||
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phylogenetic justification
Assignment of UNSM 46504 to a clade including Heterodon to the exclusion of Diadophis and Pseudoboa is based on the character combination of: 1) a quadrate with a narrow and strongly recurved distal shaft and a wide, narrow suprastapedial crest; 2) a narrow ventrally curved compound bone; 3) A parietal with a broad, well-defined skull table; 4) a supraoccipital with a well-defined sagittal crest. |
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phylogenetic reference(s)
The linked fossil has no phylogentic references. |
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| tree image (click image for full size) | ||
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Figure 1 from Head et al. (2016).
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