''Agadirichnus'' is an

ichnogenus An ichnotaxon (plural ichnotaxa) is "a taxon based on the fossilized work of an organism", i.e. the non-human equivalent of an artifact. ''Ichnotaxon'' comes from the Ancient Greek (''íchnos'') meaning "track" and English , itself derived from ...

of probable

azhdarchid Azhdarchidae (from the Persian word , , a dragon-like creature in Persian mythology) is a family of pterosaurs known primarily from the Late Cretaceous Period, though an isolated vertebra apparently from an azhdarchid is known from the Early Cre ...

pterosaurs Pterosaurs are an extinct clade of flying reptiles in the Order (biology), order Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 million to 66 million years ago). Pterosau ...

from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

(

Maastrichtian The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...

) of

Morocco Morocco, officially the Kingdom of Morocco, is a country in the Maghreb region of North Africa. It has coastlines on the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to Algeria–Morocc ...

. The

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * ...

and only ichnospecies is ''A. elegans'', representing the first named trace fossil made by a pterosaur.

Discovery

''Agadirichnus'', meaning 'trace of

Agadir Agadir (, ; ) is a major List of cities in Morocco, city in Morocco, on the shore of the Atlantic Ocean near the foot of the Atlas Mountains, just north of the point where the Sous River, Souss River flows into the ocean, and south of Casabla ...

', was first described as

lizard Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic isla ...

tracks in 1954 based on two pes prints discovered from the

Tagragra tracksite of Agadir, Morocco. Various paleontologists have since suggested different interpretations, but the type locality was unknown for a long time and the type specimen of this ichnotaxon was considered to be lost. In 2018, Masrour and colleagues designated a neotype (FSA.G.54) based on an isolated, virtually identical footprint they found on the rediscovered type locality, and reclassified this ichnogenus as that of a

pterosaur Pterosaurs are an extinct clade of flying reptiles in the order Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 million to 66 million years ago). Pterosaurs are the earli ...

, most likely an

Classification

While ''Agairnichnus'' was initially described as

tracks, other researchers have doubted this classification since 2003, when two opposing interpretations of this ichnotaxon was proposed: American paleontologists

Martin Lockley Martin G. Lockley (17 March 1950 – 25 November 2023) was a Welsh palaeontologist. He was educated in the United Kingdom where he obtained degrees (BSc and PhD) and post-doctoral experience in Geology in the 1970s. Since 1980 he has been a pr ...

and John R. Foster claimed that ''Agadirichnus'' represented

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

tracks, while French paleontologists Jean-Paul Billon-Bruyat and Jean-Michel Mazin suggested that it is a

pterodactyloid Pterodactyloidea ( ; derived from the Greek words ''πτερόν'' (''pterón'', for usual ''ptéryx'') "wing", and ''δάκτυλος'' (''dáktylos'') "finger") is one of the two traditional suborders of pterosaurs ("wing lizards"), and contai ...

pterosaurian ichnotaxon, possibly a

senior synonym In taxonomy, the scientific classification of living organisms, a synonym is an alternative scientific name for the accepted scientific name of a taxon. The botanical and zoological codes of nomenclature treat the concept of synonymy differently. ...

of '' Pteraichnus saltwashensis''. This would make ''Agadirichnus'' the first described pterosaur ichnofossil in the history of paleontology, though other researchers still noted its uncertainty due to the poor preservation of the type specimen, suggesting that this taxon might be a ''

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium,'' it may be impossible to determine whether a ...

''. In 2018, Masrour and colleagues rediscovered the type locality and found an isolated footprint, assigned as the neotype, which confirmed the validity and pterosaurian identity of this ichnotaxon. They also erected a new ichnofamily Agadirichnidae which contains both ''Agadirichnus'' and the

ichnotaxon '' Haenamichnus'' from the

Campanian The Campanian is the fifth of six ages of the Late Cretaceous epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campa ...

Uhangri Formation The Uhangri Formation (), located at the Haenam County, Haenam, South Jeolla Province, Jeollanam-do, South Korea is a non-marine geological Formation (geology), formation known with epiclastic fluvio-lacustrine sequence with minor volcaniclastics. ...

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia. It constitutes the southern half of the Korea, Korean Peninsula and borders North Korea along the Korean Demilitarized Zone, with the Yellow Sea to the west and t ...

References

{{trace-fossil-stub Ichnotaxa