comment on this calibration


 node name
Ectobius     Look for this name in NCBI   Wikipedia   Animal Diversity Web
  recommended citations Evangelista et al. 2017
  node minimum age
48.14 Ma
This fossil is from the Parachute Creek member of the Green River Formation. The upper and lower age bound for this layer are 51.24 (+/- 0.52) Ma and 48.37 (+/- 0.23) Ma, respectively. The lower age limit is based on single crystal laser incremental 40Ar/39Ar dating of volcanic phenocrysts (Smith et al., 2008).
  node maximum age
0 Ma
None specified.
 primary fossil used to date this node 
USNM 53274
Ectobius kohlsi, Vršanský, Vidlička, and Labandeira, 2014
Location relative to the calibrated node: Crown

[show fossil details]
     Locality: Parachute Creek Member
     Stratum: Green River Formation
     Geological age: Eocene, Paleogene, Cenozoic

More information in Fossilworks   PaleoBioDB

  phylogenetic justification
Vršanský et al. (2014) place this fossil as a member of either the Krasussianus or Sylvestris species group. This is supported by a number of morphological characters. The separate media and radial vein is shared with extant E. ticinus Bohn, 2004 (Sylvestris sp. group). The forewing coloration (maculae patterns) is identical to that of E. brunneri Seoane, 1879 (Sylvestris sp. group). Presence of pronotal punctae is seen in E. brunneri (Sylvestris sp. group) and E. panzeri Stephens, 1835 (Capraiellus group). The presence of two symmetrical arcuate pronotal ridges is shared with E. sylvestris (Poda, 1761), E. kraussianus Ramme, 1923 (Krasussianus sp. group), E. lagrecai Failla and Messina, 1981, and E. aetnaeus Ramme, 1927 (Sylvestris sp. group). All these features support the association of this species with extant subgenus Ectobius (Ectobius) Stephens, 1835, as opposed to the subgenus Ectobius (Ectobiola) Uvarov, 1940, which has dark spots on the tegmina and is lacking punctae. Vršanský et al. (2014) suggested that Ectobius (Ectobiola) may not be sister to Ectobius (Ectobius) but is a member of the Lapponicus species group of Ectobius. Vršanský et al. (2014) also differentiate this fossil from other Ectobius species groups in that they are lacking the pronotal ridges, have different coloration on the pronotum or tegmina, have different punctae patterns, have different shape of cerci, and have different gland morphology. Because the sister taxon to the Krasussianus and Sylvestris species groups of Ectobius are not known, this fossil should be used to calibrate the basal split in Ectobius.
  phylogenetic reference(s)
Vršanský, P., Oružinský, R., Barna, P., Vidlička, L., and Labandeira, C.C. 2014. Native Ectobius (Blattaria: Ectobiidae) from the Early Eocene Green River Formation of Colorado and its reintroduction to North America 49 million years later. Annals of the Entomological Society of America, 107:28-36
 tree image (click image for full size) 
tree image
Figure 2 from Evangelista et al. (2017).