''Parahenodus'' is an extinct genus of
henodontid placodont
Placodonts (" Tablet teeth") are an extinct order of marine reptiles that lived during the Triassic period, becoming extinct at the end of the period. They were part of Sauropterygia, the group that includes plesiosaurs. Placodonts were genera ...
only known from a skull, discovered between 2008 and 2015 and described in 2018. It lived during the
Late Triassic
The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch ...
(
Carnian
The Carnian (less commonly, Karnian) is the lowermost stage of the Upper Triassic Series (or earliest age of the Late Triassic Epoch). It lasted from 237 to 227 million years ago (Ma). The Carnian is preceded by the Ladinian and is followed by t ...
–
Norian
The Norian is a division of the Triassic Period. It has the rank of an age (geochronology) or stage (chronostratigraphy). It lasted from ~227 to million years ago. It was preceded by the Carnian and succeeded by the Rhaetian.
Stratigraphic defi ...
). The skull, named and described as ''Parahenodus atancensis'', was discovered in
Keuper
The Keuper is a lithostratigraphic unit (a sequence of rock strata) in the subsurface of large parts of west and central Europe. The Keuper consists of dolomite, shales or claystones and evaporites that were deposited during the Middle and Late ...
Facies
In geology, a facies ( , ; same pronunciation and spelling in the plural) is a body of rock with specified characteristics, which can be any observable attribute of rocks (such as their overall appearance, composition, or condition of formatio ...
of the Castilian Branche of the Iberian Range in the reservoir of El Atance (
Sigüenza
Sigüenza () is a city in the Serranía de Guadalajara comarca, Province of Guadalajara, Castile-La Mancha, Spain.
History
The site of the ancient ''Segontia'' ('dominating over the valley') of the Celtiberian Arevaci, now called ('old town ...
,
Spain
, image_flag = Bandera de España.svg
, image_coat = Escudo de España (mazonado).svg
, national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond")
, national_anthem = (English: "Royal March")
, i ...
). It was the
sister taxon
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree.
Definition
The expression is most easily illustrated by a cladogram:
Taxon A and t ...
to ''
Henodus
''Henodus'' (from el, ἑνός , 'one' and el, ὀδούς , 'tooth') is an extinct placodont of the Late Triassic period during the early Carnian age. Fossils of ''Henodus chelyops'' were found in the Estherienschichten Member of the Grab ...
''.
References
{{Taxonbar, from=Q55214658
Fossil taxa described in 2018
Placodonts
Sauropterygian genera