comment on this calibration
Loxocemidae
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
» Henophidia
| node name Loxocemidae Look for this name in NCBI Wikipedia Animal Diversity Web | ||
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recommended citations http://palaeo-electronica.org/content/fc-6 Head, 2015 |
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node minimum age 35.2 Ma Minimum age is based on faunal correlation of Medicine Pole Hills fossil localities (Bowman County, North Dakota) with Flagstaff Rim localities (Natrona County, Wyoming), which are overlain by an ash layer (Ash B) that is 40Ar/39Ar dated at 35.41 ± 0.14 Ma (Obradovich et al., 1995). Smith (2011) recalculated the minimum estimate for the Medicine Pole Hills local fauna at 35.2 Ma. | ||
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node maximum age 0 Ma None specified. | ||
| primary fossil used to date this node | ||
PTRM 19378 | ||
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phylogenetic justification
PTRM 19378 is united with Loxocemidae on the basis of: 1) dorsal head expanded into broad plate; 2) dorsal head lies wholly in saggital plane; 3) well-defined lip present on lateral side of dorsal margin (Smith, 2013). |
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phylogenetic reference(s)
Smith, K.T. 2013. New constraints on the evolution of the snake clades Ungaliophiinae, Loxocemidae and Colubridae (Serpentes), with comments on the fossil history of Erycine boids in North America. Zoologischer Anzeiger, 252:157-182.
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| tree image (click image for full size) | ||
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Figure 1 from Head (2015).
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