Hastichthys totonacus sp. nov., a North American Turonian dercetid fish (Teleostei, Aulopiformes) from the Huehuetla quarry, Puebla, Mexico
Por:
Alvarado-Ortega, Jesus, Alberto Diaz-Cruz, Jesus
Publicada:
1 ene 2021
Resumen:
A new fossil needlefish species is named in this work as Hastichthys
totonacus, based on specimens from the marine Turonian deposits of the
Agua Nueva Formation, exposed in the Huehuetla quarry, into the Sierra
Norte region of Puebla, Mexico. The osteology of this new species shows
a diagnostic character of the order Aulopiformes, the occurrence of
epipleurals bones associated with abdominal centra, at least from the
centrum 2. This new species also shows the most distinctive features of
the family Dercetidae and genus Hastichthys, including the longirostrine
head; the elongated body; two pairs of triangular and expanded
transverse processes in the abdominal centra; the low and elongated
neural arches on abdominal centra bearing short neural spines; a row of
triradiate scutes on each body flak; and the anterior part of maxilla
and dentary bones are ornamented with longitudinal and parallel ridges.
Hastichthys totonacus is the second species in the genus and differs
from the type species, H. gracilis, in having a relatively shorter body
with 59 total centra, the head length is about 38% of the standard
length, the dorsal fin has seven rays, and the anal fin has eight rays.
The inclusion of this new species in different phylogenetic analyses
reveals that the interrelationships of the Dercetidae family are poorly
resolved and that H. totonacus sp. nov. and H. gracilis form a
monophyletic group. Additionally, the species Rhynchodercetis regio,
from the Turonian sediments of the Agua Nueva Formation, exploited in
the Vallecillo quarry, Nuevo Leon, northern Mexico, is also placed into
the genus Hastichthys because it has the most prominent character of
this genus, the tips of rostrum and mandible are ornamented with
longitudinal and parallel striae and ridges. The occurrence of these two
Mexican Turonian species extends the temporal and geographical
distribution of the genus Hastichthys, from the Cenomanian deposits of
the western Tethys Sea realm preserved in the Middle East toward the
Turonian deposits of eastern Mexico, at the southern end of North
America.
Filiaciones:
Univ Nacl Autonoma Mexico, Inst Geol, Circuito Invest S-N,Ciudad Univ, Mexico City 04510, DF, Mexico
Univ Nacl Autonoma Mexico, Posgrad Ciencias Biol, Circuito Invest S-N,Ciudad Univ, Mexico City 04510, DF, Mexico
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