Gruipeda Panin & Avram, 1962

Abbassi, Nasrollah, Salehi Tinooni, Mohammad, Ghorbani Dehnavi, Mahdi, Shakeri, Safoora & Eshaghi, Ali, 2024, Oligocene vertebrate footprints from the Lower Red Formation, Central Iran, Fossil Record 27 (2), pp. 265-287 : 265-287

Ichnogenus Gruipeda Panin & Avram, 1962

Type ichnospecies.

Gruipeda maxima Panin & Avram (1962)

Revised diagnosis.

Footprints showing four-digit imprints, three of which ( II to IV) are directed forward and larger, the fourth (I), directed backward, spur-like and short. The interdigital angle between digits II and III and between digits III and IV are commonly less than 70 °. The hallux imprint is posteromedially directed; the interdigital angle between digits I and II being smaller than that between digits I and IV. When present, digital pad traces display the relationship I: 2, II: 2, III: 3, IV: 4. Webbing trace absent (emended from de Valais and Cónsole-Gonella 2019).

Discussion.

Gruipeda is a well-known bird footprint, and mostly reported as tetradactyl from the Cenozoic sediments. Panin and Avram (1962) established Gruipeda for tetradactyl small bird footprints with a short description and without type materials. Sarjeant and Langston (1994) emended its diagnosis and considered number, position and shape of digit imprints, and interdigital angel, as main characteristics of Gruipeda . de Valais and Cónsole-Gonella (2019) however followed Sarjeant and Langston (1994) and reformulated the diagnosis of Gruipeda by extending the description of interdigital angles and number of digital pad traces. Numerous ichnospecies have been introduced for Gruipeda based on original type materials or by new recombination from other ichnogenera. Abbassi et al. (2015, in press) listed the following ichnospecies:

Gruipeda maxima Panin & Avram, 1962 .

Gruipeda becassi Panin & Avram, 1962 .

Gruipeda disjuncta Panin & Avram, 1962 .

Gruipeda minor Panin, 1965 .

Gruipeda intermedia Panin, 1965 .

Gruipeda filiportatis Vialov, 1965 .

Gruipeda grus Panin et al., 1966 .

Gruipeda abeli Lambrecht, 1938 .

Gruipeda calcarifera Sarjeant & Langston, 1994 .

Gruipeda diabloensis Remeika, 1999 .

Gruipeda lambrechti Mirzaie Ataabadi & Khazaee, 2004 .

Gruipeda dominguensis de Valais & Melchor, 2008.

Gruipeda fuenzalidae Covacevich & Lamperein, 1970 .

Gruipeda vegrandiunus Fiorillo et al., 2011 .

Gruipeda limosa Rădan & Brustur, 1993 .

Panin and Avram (1962) established Charadriipeda disjuncta as a tridactyl bird footprint lacking a digit I imprint. Sarjeant and Langston (1994) recombined it as Gruipeda disjuncta . Because Charadriipeda disjuncta is a true tridactyl this recombination is not confirmed. Based on this reason, the recombination of Charadriipeda ( Panin, 1965) as Gruipeda minor by Sarjeant and Langston (1994) is not correct. Avipeda filiportatis Vialov (1965) was recombined as Gruipeda filiportatis by Sarjeant and Langston (1994) but later replaced under Ardeipeda by Lockley and Harris (2010). Sarjeant and Langston (1994) considered Iranipeda abeli ( Lambrecht, 1938) as Gruipeda abeli but Abbassi et al. (2016) and Abbassi et al. (2024) reevaluated its taxonomic position and considered Iranipeda abeli as valid. Melchor in Abbassi et al. (in press) listed Gruipeda grus , Gruipeda diabloensis , Gruipeda limosa as nomina dubia and Gruipeda minor and Gruipeda vegrandiunus equal to Avipeda . He classified Gruipeda into three groups of ichnospecies considering the footprint length (including the hallux): 1) G. lambrechti , G. intermedia , G. filiportatis and G. maxima that are large ( FL h = 120–172 mm); 2) G. becassi and G. limosa have an intermediate size ( FL h = 55–65 mm); and 3) G. fuenzalidae , G. calcarifera , G. dominguensis and G. diabloensis that are small ( FL h = 27–35 mm).