A new small duckbilled dinosaur (Hadrosauridae: Lambeosaurinae) from Morocco and dinosaur diversity in the late Maastrichtian of North Africa

In the Late Cretaceous, northern and southern hemispheres evolved distinct dinosaurian faunas. Titanosaurians and abelisaurids dominated the Gondwanan continents; hadrosaurids, ceratopsians and tyrannosaurs dominated North America and Asia. Recently, a lambeosaurine hadrosaurid, Ajnabia odysseus, was reported from the late Maastrichtian phosphates of the Oulad Abdoun Basin Morocco, suggesting dispersal between Laurasia and Gondwana. Here we report new fossils from the phosphates of Morocco showing lambeosaurines achieved high diversity in the late Maastrichtian of North Africa. A skull represents a new dwarf lambeosaurine, Minqaria bata. Minqaria resembles Ajnabia odysseus in size, but differs in the ventrally positioned jugal facet and sinusoidal toothrow. The animal is small, ~ 3.5 m long, but the fused braincase shows it was mature. A humerus and a femur belong to larger hadrosaurids, ~ 6 m long, implying at least three species coexisted. The diversity of hadrosaurids in Europe and Africa suggests a dispersal-driven radiation, with lambeosaurines diversifying to take advantage of low ornithischian diversity. African lambeosaurines are small compared to North American and Asia hadrosaurids however, perhaps due to competition with titanosaurians. Hadrosaurids are unknown from eastern Africa, suggesting Moroccan hadrosaurids may be part of a distinct insular fauna, and represent an island radiation.


Geographic and geological setting
The new hadrosaurid remains come from the marine phosphates of the Oulad Aboun Basin, in Khouribga Province.The new small lambeosaurine, Minqaria bata, comes from the mines at Sidi Chennane, the same locality that produced Ajnabia odysseus 7 , and is based on an associated skull.The other fossils come from Sidi Daoui and Mrah Lahrach (Fig. 1) and were found as isolated elements, as is typical of the phosphates.
The Phosphates consist of phosphatic sands, marls, and limestones (Fig. 2), deposited in an embayment along the eastern margin of the Atlantic from the late Cretaceous to the early Eocene 15,16 .The Phosphates are divided into beds or 'couches' .Couche III is Cretaceous; Couche II, I and 0, are Paleogene (Danian-Ypresian).Couche   15 .Diagnosis.Small lambeosaurine characterized by the following character combination, which also differentiates it (where the specimens overlap) from Ajnabia odysseus.Jugal articulation lies very low on maxilla (autapomorphic within lambeosaurinae); ectopterygoid ridge ends at jugal articulation.Ectopterygoid ridge concave in lateral and dorsal views, narrower posteriorly than anteriorly.Neurovascular foramina arranged in a row.Highly domed frontoparietal, with extensive contribution of parietal to the dome, and a triangular parietal table.Maxillary toothrow sinusoidal in lateral or ventral views, with a deep buccal fossa.Dentary short and deep, occlusal margin straight; symphyseal process strongly extended anteriorly, and with straight ventral margin.Alveolar ridges of maxilla and dentary poorly developed.Teeth small, with narrow apices, broad central ridges, and rugose enamel.

Description and comparisons.
Maxilla.The maxilla (Figs. 3, 4) is 195 mm long as preserved, but is incomplete anteriorly and dorsally.Alveoli become much smaller anteriorly (Fig. 4b), suggesting the maxilla did not extend much further; perhaps 15-20% of the bone's length is missing anteriorly.There are 27 alveoli preserved and perhaps two or three on the missing part of the maxilla.This is low for Lambeosaurinae, which typically have more than thirty teeth [40][41][42][43] , but a low tooth count occurs in Ajnabia odysseus 7 and Canardia garonnensis 44 .Because hadrosaurids added tooth positions as they grew 40 , this feature may result from the animal's small size.
In lateral view (Fig. 4a), the maxilla is short anteroposteriorly and tall dorsoventrally, as in other hadrosaurids 11 especially Lambeosaurinae 7,45 , and subrectangular.The maxilla's anterodorsal margin extends up and forms a broad dorsal process, as in Saurolophinae 11 and Arenysaurini including Canardia garonnensis and Pararhabdodon isonensis 44 ; the maxilla is broken here in Ajnabia 7 .In Lambeosaurini 46 and Parasaurolophini 42,45 , the maxilla is shallow anterior to the jugal articulation, with the premaxilla approaching the jugal articulation.The maxilla is narrow in dorsal (Fig. 4d) or ventral view (Fig. 4b), similar to Pararhabdodon isonensis; maxillae of Ajnabia and Canardia are broad in dorsal or ventral view.
The jugal facet lies very low on the maxilla (Fig. 4a), unlike all other Lambeosaurinae, where the jugal facet lies high on the maxilla 7,45 , an autapomorphy of the species.Here Minqaria resembles saurolophines such as Kritosaurus and Edmontosaurus 45 .The jugal articulation is convex anteroventrally, then forms a straight edge where it extends above the ectopterygoid ridge.Extension of the jugal articulation posterodorsally above the ectopterygoid ridge is an apomorphy of Lambeosaurinae 7,45 .
Five neurovascular foramina extend in a line from below the jugal articulation anteriorly onto the maxilla's lateral surface (Figs.4a, b).This differs from Ajnabia 7 , where a pair of neurovascular foramina lie below the jugal articulation.Neither is this condition seen in Pararhabdodon 44 , but it is similar to Canardia 44 .The ectopterygoid ridge (Fig. 4a) extends from the jugal articulation back along the maxilla's posterior dentigerous.It forms a low, broad ridge, similar to that of Ajnabia 7 ; the ectopterygoid ridge in Canardia and Pararhabdodon is narrower and better defined 44 .The ridge has a distinctly concave ventral margin, similar to Canardia, those of Ajnabia and Pararhabdodon are straight in lateral view 44 .In dorsal view (Fig. 4d), the shelf formed by the ectopterygoid ridge narrows towards the back of the jaw; that of Ajnabia 7 becomes broader, and is more convex.
In ventral view (Fig. 4b), the toothrow is sinusoidal.The toothrow curves inwards at the front of the jaw, outwards near the middle of the maxilla, then curves inwards again at the back.Ajnabia 7 has a similar but less extreme curvature, the toothrow of Pararhabdodon is only weakly sinusoidal 48 .The toothrow in Canardia is strongly curved outward posteriorly 44 , but this feature may be exaggerated by crushing.
Maxillary dentition.Several unerupted teeth lie partially exposed in the maxillae (Figs. 4, 5).These teeth are typical of hadrosaurids in being much taller than wide 11 and resemble lambeosaurines 41,46,[49][50][51] in their tall, narrow, lanceolate shape (Fig. 5).The tips of the crowns are narrower and more pointed than in Ajnabia odysseus 7 .As in other hadrosaurids, maxillary teeth bear enamel on the lateral surface of the tooth only 11 .The enamel has a distinctly coarse, roughened texture, Ajnabia 7 has smoother enamel.
The mesial and distal carinae have highly reduced denticles, a derived feature shared with other Arenysaurini 7 , but unlike most Lambeosaurinae 11 where denticles are large and well-developed.The single central ridge is slightly offset towards the distal carina, as in Ajnabia 7 .The central ridge is low and rounded; in Ajnabia it is taller and narrower.The lateral, enamel-covered surface of the tooth is not planar, but instead curls onto the apex of the tooth, as in Ajnabia 7 .
The frontals contact each other medially, the parietal posteriorly (Fig. 6a), the laterosphenoid ventrally.Although the sutures are visible, the frontals are tightly joined to each other and the parietal by a strongly interdigitating contact, similar to that seen in other lambeosaurines 52 .The degree of interdigitation is stronger than in Arenysaurus 50 , but not developed to the same degree as seen in Corythosaurus 52 .In places the frontoparietal suture is well-developed, but in others is difficult to see, due either to tight knitting of bones or perhaps partial fusion of bones.The tight knitting of the bones suggests the animal is mature.
The frontals form a well-developed dome, as in Arenysaurus 50 , although the frontals of Minqaria are less strongly domed than in Arenysaurus, where the posterior margin of the frontals rises up almost vertically.A well-developed dome also occurs in Jaxartosaurus.The frontals of Lambeosaurini 40 and Parasaurolophini 53,54 are less strongly domed than in Minqaria or Arenysaurus.This may be partly size-related, as juvenile lambeosaurines, e.g.Hypacrosaurus, show stronger frontal domes than adults 40 .
Laterally, frontal postorbital processes are slightly concave.Posteriorly, the frontals form a V-shaped notch to receive a triangular tab from the parietal.
The parietal contacts the frontals anteriorly (Fig. 6a), the laterosphenoids anteroventrally, and the supraoccipital posteriorly (Fig. 6e, f).Along the midline the parietal forms a broad, triangular anterior process projecting  contributing to the frontoparietal dome occurs in juvenile Corythosaurus but is reduced in adults 52 .In the basal hadrosauroid Eotrachodon, a triangular process projects between the frontals 55 , but does not contribute to the dome; the saurolophines Edmontosaurus 56 and Gryposaurus 52 lack this triangular process.The parietal's anterolateral processes angle forward and wrap around the back of the frontals.A similar morphology occurs in Arenysaurus, Jaxartosaurus, the lambeosaurin Corythosaurus 54 and the parasaurolophin Charonosaurus.The anterolateral processes project laterally in Saurolophinae 52,56 and Eotrachodon 55 .The parietal has a small, triangular parietal table and behind this a parietal sagittal crest; in Arenysaurus 50 the parietal lacks a parietal table and the sagittal crest extends further forward towards the frontals.
The parietal is broadly arched between the supratemporal fenestrae, with a narrow sagittal crest as in Hypacrosaurus 40 ; the parietal of Arenysaurus is narrower 50 .The parietal is moderately elongate, resembling Arenysaurus, Lambeosaurini 52 and Parasaurolophini 54 ; the parietal of Tsintaosaurus is shorter; the parietal of Saurolophinae tends to be more elongate 52,56 .Ventrolaterally, the parietal curls down to contact the orbitosphenoids, laterosphenoids, and prootics.
Laterally (Fig. 6e, f), the laterosphenoid and prootic form the lateral walls of the braincase.Ventrally, the basisphenoid projects down forming a pair of long basipterygoid processes.The basipterygoid processes project caudally as in Arenysaurus 50 and Olorotitan 42 ; the basipterygoid processes project ventrally in Hypacrosaurus altispinus 40 and the saurolophines Brachylophosaurus canadensis 57 , and Edmontosaurus regalis 56 and anteroventrally in Parasaurolophus cyrtocristatus 53 .
Posterior to the basipterygoid processes, the basisphenoid is markedly concave, as in Arenysaurus 11 .The basisphenoid's alar process is well-developed and posterolaterally projecting.It is similarly well-developed in Arenysaurus, but projects more laterally.The alar process is small in most hadrosaurids except brachylophosaurins 57 .Posteriorly, the supraoccipital is tall and triangular, with a midline crest not seen in other hadrosaurids 40,54,56 .The foramen magnum and occipital condyle are obscured by hard matrix.Two cranial nerves perforate the exoccipital, (Fig. 6f) forming the exits of the hypoglossal (XII) nerve posteriorly and of the glossopharyngeal and vagoaccessory nerves (IX-XI) anteriorly through what appears to be a single metotic foramen (Fig. 6f).
Dentary.The dentary (Fig. 7) is short and deep, similar to Blasisaurus canudoi 49 , Corythosaurus casuarius 47 or Hypacrosaurus altispinus 40 , and unlike the elongate dentary of the arenysaurins Arenysaurus ardevoli 50 and Koutalisaurus kohlerorum 58 , or lambeosaurines such as Amurosaurus riabinini 41 , Olorititan arharensis 42 , Sahaliyania elunchunorum 59 , and Parasaurolophus tubicen 51 .The dentary's dorsal and ventral margins are roughly parallel www.nature.com/scientificreports/ in lateral view (Fig. 7a), giving it a rectangular shape.The dentary's dentigerous margin is straight for most of its length, but turns downwards at the anterior and posterior end of the toothrow, similar to Blasisaurus 49 and Koutalisaurus 58 ; the dentigerous margin of Arenysaurus 9 is more convex.The dentary's ventral margin is nearly straight, with a slight inflection where the symphyseal process projects anteroventrally.This weak inflection and the anteriorly projecting symphyseal process are shared with Koutalisaurus 58 ; in Arenysaurus 50 and Blasisaurus 49 , the ventral margin of the jaw curves more and the symphyseal process projects more strongly downward.The posteroventral margin of the dentary is weakly convex.The coronoid process is strongly projected laterally as in other hadrosaurids.
In medial view (Fig. 7b), there are at least 25 alveoli, formed as long, narrow grooves to accommodate multiple replacement teeth, as in other Hadrosauridae 11 .Alveolar slots are shallower than in Ajnabia 7 .Alveoli extend three-quarters of the way down the dentary.Alveoli extend further ventrally in Blasisaurus 49 , Koutalisaurus 58 , and Hypacrosaurus 40 , and almost all the way down in Arenysaurus 50 .The Meckelian canal is visible medially as in Blasisaurus and Koutalisaurus 58 ; it runs ventrally and is concealed in medial view in Arenysaurus 50 and Hypacrosaurus 40 .In dorsal view (Fig. 7c), the dentary is narrow and the toothrow has a sinuous curve matching the curve of the maxillary toothrow.

Description and comparisons
Humerus.MHNM.KHG.1483 is a left humerus missing its proximal end (Fig. 8).The bone measures 278 mm long, and likely measured around 435 mm when complete.Assuming proportions similar to Corythosaurus casuarius 60 , MHNM.KHG.1483 was around 5.9 m in length.
In lateral view (Fig. 8a), the humerus is long and gracile.It has a weak sigmoidal curvature, the shaft being bowed anteriorly at the level of the deltopectoral crest, and the distal shaft being bowed posteriorly.The distal shaft is weakly curved, as in other lambeosaurines 54 , including the arenysaurins Canardia garonnensis 44 and cf.Pararhabdodon isonensis 61 ; the distal shaft is more strongly curved in Saurolophinae 62,63 , but straight in some basal hadrosauroids 64 .
In posterior view (Fig. 8c), the humerus is narrow at midshaft and broadly flared distally.The radial and ulnar condyles are well-developed.A deep olecranon fossa separates the radial and ulnar condyles, and extends about halfway up the shaft.
The prominent deltopectoral crest (Fig. 8b) projects strongly anterolaterally.The distal margin is strongly concave as in other lambeosaurines 44,54 and saurolophines 62,63 , but unlike Hadrosaurus foulkii 65 or basal hadrosauroids 64,66 where it is weakly concave, or straight.The femur's proximal end is crushed (Fig. 9a), and the bone is difficult to differentiate or physically separate from the consolidated matrix, complicating comparisons.The shaft is large in diameter despite the animal's small size.It is anteroposteriorly crushed but even accounting for crushing, it is robust, even compared to large hadrosaurids like Magnapaulia laticaudus 43 and Olorotitan arharensis 42 .
The femoral shaft appears to be relatively straight in anterior view (Fig. 9a), as in Lambeosaurinae 43,67 , Edmontosaurini 63 , and Hadrosaurini 65 .In basal hadrosauroids, the femoral shaft is bowed 66,68 with the condyles more obliquely oriented relative to the femoral shaft, suggesting a less vertical femoral posture.
In medial or lateral view (Fig. 9b, d), the shaft has a gentle sigmoidal curvature, with the proximal shaft being bowed posteriorly, and the distal end bowed anteriorly.This sigmoid curvature occurs in the type of Orthomerus dolloi 68 , but not in other specimens 69 , and in Parasaurolophini 54 , but not in Lambeosaurini 43 .The femur of the arenysaurin Adynomosaurus arcanus is straight in lateral view 67 , but has also been reconstructed.The femoral shaft is also straight in some saurolophines, e.g.Secernosaurus koerneri 70 and Saurolophus osborni 71 .Sigmoidal curvature of the femoral shaft occurs in some basal hadrosauroids, including Bactrosaurus johnsoni 72 and Telmatosaurus transsylvanicus 68 , but it is straighter in others, such as Gobihadros mongoliensis 64 .
Medial and lateral condyles are well-developed and project anterior and posterior to the shaft as in other hadrosaurids.The cranial intercondylar groove is broadly open (Fig. 9c).There is a deep posterior intercondylar groove.Because body mass is tightly correlated with limb bone dimensions, particularly diameters and circumferences 75 , it is possible to make a mass estimate from the femur.Given a femur circumference of 238 mm and assuming a ratio of humerus circumference to femur circumference of 0.651, as seen in Corythosaurus 76 , the corresponding humeral circumference should be 154.9.A regression of humerus + femoral circumference suggests a mass of 1066 kg based on the equation for quadrupeds from Campione and Evans 75 and 1099 kg for the equation for quadrupeds from Campione 2017 77 for this ~ 4.5 m long animal.The Sidi Daoui humerus suggests a larger, 5.9 m long animal, approximately twice this mass, but smaller than contemporary Laurasian hadrosaurids.

Discussion
Ontogeny.Skeletal fusion can be used as a proxy for maturity in dinosaurs.Although some elements (e.g.parietals) can fuse early in ontogeny, extensive skull fusion occurs as animals approach full size 40,78,79 .Extensive co-ossification of the braincase in the Minqaria holotype is therefore consistent with skeletal maturity.No clear www.nature.com/scientificreports/exoccipital-prootic suture is visible, suggesting these elements are fused; fusion between these bones occurs late in ontogeny in lambeosaurines 40 .The prootic-laterosphenoid suture is also indistinct suggesting fusion; the laterosphenoid-parietal suture is visible anteriorly but not posteriorly, suggesting partial fusion.This extensive cranial fusion contrasts with juvenile and subadult lambeosaurines 40,80 , showing MHNM.KH.1484 is a mature adult.
Frontal-frontal and frontal-parietal sutures are also highly interdigitated and the midline of the parietal forms a sagittal crest, as in adult lambeosaurines 40,81 .Finally, surface texture of the bone suggests maturity.Juvenile lambeosaurines, like other juvenile dinosaurs, show striated bone textures associated with rapid growth 82 ; but the bone of MHNM.KH.1484 lacks striated texture.
Systematics.Minqaria is distinguished from Ajnabia by the shape of the maxilla (Fig. 4), which has a more ventrally placed jugal facet, a curved ectopterygoid ridge, a more sinusoidal toothrow, and neurovascular foramina arranged in a line.However, Minqaria closely resembles Ajnabia and other arenysaurins in its small size, and many anatomical features.Derived features uniting Minqaria with arenysaurins include the reduced number of maxillary alveoli (shared with Ajnabia and Canardia), a posteriorly shifted dental midline ridge (shared with Ajnabia, Blasisaurus, and the Serrat del Rostiar lambeosaurine); a strongly domed frontal (shared with Arenysaurus, and the Basturs lambeosaurine).The dentary predentary process appears to resemble that of other arenysaurins in being triangular, with straight dorsal and ventral margins, although damage makes comparisons difficult.Accordingly, Minqaria is recovered within Arenysaurini, a lambeosaurine clade endemic to Europe and North Africa.
The humerus and femur appear to represent lambeosaurines.The humerus resembles Hadrosauridae, including Lambeosaurinae, in having a concave distal edge to the deltopectoral crest; the weak sigmoidal curvature of the shaft resembles Lambeosaurinae.Neither is unique to Lambeosaurinae, but this character combination seems to be unique to lambeosaurines.The femur resembles Hadrosauridae in having a straight shaft in anterior view.The sigmoidal curvature seen in lateral view is seen in a variety of taxa, but is consistent with referral to Lambeosaurinae.The long, low fourth trochanter suggests affinities with Arenysaurini.Neither the humerus nor femur are diagnostic, and are referred to Lambeosaurinae indet.Given their large size, they are likely distinct from either Ajnabia or Minqaria, but additional fossils are required to test this hypothesis.

Phylogeny and biogeography
Although the lambeosaurine affinities of the Moroccan hadrosaur Ajnabia have been questioned 83 , the new material corroborates the presence of Lambeosaurinae in Africa.Other analyses have recovered Ajnabia as a lambeosaurine 84,85 but not a monophyletic clade of European and African species.The differences result from inclusion of novel characters (e.g. the triangular predentary process of the mandible) and recodings of characters of the jaws and teeth that were found to unite Arenysaurini.We argue the results found here-with small-bodied European and African lambeosaurines representing a single lineage-are more parsimonious than the alternatives, which require multiple overwater dispersals to colonize Iberia, long ghost-lineages, and repeated evolution of small body size.The simplest explanation of all the data is that European and African lambeosaurines represent one lineage.More complete remains of the African and European arenysaurins are needed to better resolve their systematics, however.
Our phylogenetic analysis suggests Lambeosaurinae initially diversified in Asia, then saw dispersals into North America by Parasaurolophini and Lambeosaurini.Dispersal from Asia into Europe was followed by dispersal into North Africa.Multiple dispersals from Europe to Africa seem less parsimonious than a single dispersal (Fig. 10), but are not impossible, particularly given the distinctive morphologies of Ajnabia and Minqaria.
The precise number of dispersals in hadrosauroids remains unclear due to conflicting tree topologies.The existence of basal hadrosauroids and lambeosaurines in Europe suggests at least two dispersals 7 , followed by dispersal of lambeosaurines into Africa 7 .The discovery of basal hadrosauroids in South America suggests two dispersals into South America, one by basal hadrosauroids 83 and one by kritosaurins 86,87 , which dispersed into Antarctica 86 .Hadrosaurines dispersed into Appalachia; reinterpretation of Lophorhothon as a basal hadrosauroid suggests saurolophines did not disperse into Appalachia 88 .Absent any strong evidence for land bridges, and given the limited number of dispersals of dinosaurs between these land masses, the simplest hypothesis is that hadrosauroids colonized Europe, Africa, Appalachia, South America and Antarctica via oceanic dispersal 7 .
Diversity of North African lambeosaurines.The discovery of Ajnabia was surprising given that, during the Cretaceous, hundreds of kilometers of water separated North Africa from Eurasia.The new lambeosaurine fossils not only confirm the existence of lambeosaurines in North Africa, but shows they were diverse.Although Minqaria is similar in size to Ajnabia, differences in the shape of the maxilla, the position of the jugal contact, and especially the tooth morphology suggest that it likely occupied a distinct ecological niche.Meanwhile, the relatively larger size of the Daoui and Mrah Lahrach lambeosaurines suggests they occupied a niche distinct from the smaller Ajnabia and Minqaria.The different morphologies and sizes (Fig. 11) suggest that we are sampling a diverse radiation (Fig. 10).The relatively robust femur of the Mrah Lahrach animal is also curious suggesting an unusual locomotor strategy and perhaps ecology.
Given the long distance and deep ocean channels separating North Africa from Europe 89 , a single dispersal seems more likely than multiple dispersals.If so, Lambeosaurinae may have arrived in the Maastrichtian or Campanian, possibly during the Campanian-Maastrichtian lowstand event, then diversified over several million years.A possible hadrosaurid from the early Maastrichtian of Angola would potentially constrain lambeosaurine dispersal to the early Maastrichtian or late Campanian 5 , if it does represent a hadrosaurid.Given the rapid rates of speciation seen in colonizing lineages such as Galapagos finches 90 and island anoles 91 , and high rates of turnover seen in herbivorous dinosaurs 92,93  Absence of competing ornithischians may have driven diversification.In contrast to North America or Asia, where hadrosaurids and ornithischians were highly diverse, no ornithischians other than lambeosaurines are known from the Maastrichtian of Morocco.Similarly, diversity of the European Lambeosaurinae may be high, with a wide range of jaw morphologies and species occurring, because hadrosaurids in Europe had limited competition, with relatively few other ornithischian lineages present.These included rhabdodontid iguanodontians 94 , basal hadrosauroids [95][96][97] , and struthiosaurine ankylosaurs 98,99 .North American lambeosaurines competed with multiple lineages of hadrosaurids as well as other ornithischians such as thescelosaurids, pachycephalosaurids, leptoceratopsids, nodosaurids and ankylosaurids, as well as herbivorous coelurosaurs such as ornithomimids, deinocheirids, caenagnathids, and possibly troodontids 100 .
By the latest Maastrichtian, lambeosaurines saw regional extinction in North America, disappearing from the northern Great Plains, but persisting in the south 101 .Meanwhile, lambeosaurines in Europe and especially the Ibero-Armorican landmass became highly diverse at the end of the Cretaceous 44,102,103 .A comparable diversification appears to have taken place in North Africa.These patterns emphasize the highly local nature of dinosaur diversity; local extinctions or radiations may not capture global patterns in dinosaur diversification and extinction.
The new fossils confirm that African hadrosaurids were small by hadrosaurid standards.The femur suggests an animal around 4.5 m in length and weighing ~ 1000 kg; the humerus suggests a substantially larger animal.This is large by the standards of extant mammals, but small by the standards of hadrosaurids.Minqaria was a  smaller around 3.5 m in length, which suggests a weight of around 250 kg, but the fusion of the braincase indicates it was somatically mature.Ajnabia was likely similar in size given the mature bone texture of the holotype.
Iberian arenysaurins resembled African forms in being relatively small.Small species include indeterminate species from Lleida 61,104 falling within the size range of Minqaria and Ajnabia.In addition, very small lambeosaurine remains belonging to mature individuals of about 2 m body length have been described from latest Cretaceous sites of the Spanish Pyrenees 105 .The Basturs Poble lambeosaurine is somewhat larger, with a femur length of 645 mm, comparable to the larger hadrosaurids known from Morocco.
While hadrosaurids in North America and Asia occupied megaherbivore niches, Moroccan and European lambeosaurines occupied small-and medium-sized herbivore niches.These patterns might result from the low diversity of competing small herbivores, and titanosaurian sauropods outcompeting lambeosaurines for megaherbivore niches.
Curiously, ornithischians occur in the latest Cretaceous of East Africa and Oman but do not appear to represent lambeosaurines.Ornithopods found in the Maastrichtian of Kenya represent non-hadrosaurid ornithopods (J.Sertich, pers.comm.2023).Likewise, hadrosauroids from Oman 6 represent non-hadrosaurids (D.Baastians, pers.comm.2023).That lambeosaurines are (so far) unknown from East Africa or the Arabian plate could result from geographic barriers to dispersal.It is conceivable that the Trans-Saharan Seaway may have divided Africa into a series of smaller landmasses 39 , with endemic dinosaur faunas, but sampling remains and issue and more dinosaur fossils are needed from Africa to test this hypothesis.

Conclusions
A hadrosaurid from the latest Maastrichtian phosphates of Sidi Chennane, Morocco, is distinct from Ajnabia odysseus and represents a new arenysaurin, Minqaria bata.Minqaria differs from Ajnabia in jaw and tooth morphology, suggesting it occupied a distinct niche.Fusion of cranial elements shows that it was mature despite its small size (~ 3.5 m), confirming the existence of small hadrosaurids in North Africa.Similarities with the European Arenysaurus provide further evidence for dispersal of lambeosaurines between the Ibero-Armorican landmass and Africa.A humerus from Sidi Daoui and a femur from Mrah Lahrach belong to larger individuals, suggesting at least three hadrosaur species occur in the phosphates.Even as lambeosaurines declined in the Maastrichtian of North America, they diversified in Africa.

Methods
Phylogenetic analysis was conducted using a modified version of the character-taxon matrix from Longrich et al. 7 , which is derived from the matrix Kobayashi et al. 63 .Characters are from Xing et al. 109 Kobayashi et al. 63 , and Longrich et al. 7 and 14 new characters were added to help resolve lambeosaurine relationships, for a total of 380 morphological characters (see SI). Two characters were excluded from analysis (87 is made redundant by two new characters; 193 was added by a previous analysis but the character description was not specified).Geographic distribution was included in addition to morphology, because biogeography shows strong phylogenetic signal, with closely related species inhabiting the same landmass 110 .Biogeography was coded as a series of binary characters rather than a single, multi-state character 7 since this allows implied weighting to assign each biogeographic character its own weight, rather than to assume all dispersals are equally probable.Four taxa were added; Minqaria bata, the Daoui hadrosaurid, the Sidi Chennane hadrosaurid, and Tlatolophus galorum.
Analyses were run in TNT 111 , using a new technology search algorithm and default settings for implied weighting (K = 3), and a strict consensus was estimated; analysis was repeated in PAUP 4.0 b10 in implied weighting and the same K = 3 under a heuristic search until 100,000 trees were recovered; this produced an identical strict consensus.TNT returned 7 trees with a score of 120.23435.The resulting strict consensus (Fig. 10) has a CI of 0.3669, an RI of 0.8244, and a rescaled consistency index of 0.3025 (for full tree, see SI).

Figure 1 .
Figure 1.Map showing localities that produced the fossil specimens described in this paper.(A), location of the Oulad Abdoun Basin, central Morocco; (B), localities of hadrosaurids recovered from Sidi Daoui, Mrah Lahrach, and Sidi Chennane.

Figure 2 .
Figure 2. Synthetic stratigraphic column of the Phosphates of the Oulad Abdoun Basin of Morocco, showing position of hadrosaurid fossils in Upper Couche III, late Maastrichtian.After Kocsis et al. 15 .

Figure 10 .
Figure 10.Evolutionary tree of Lambeosaurinae.European and African lambeosaurines are placed in Arenysaurini, a basally-diverging group of lambeosaurines.

Figure 11 .
Figure 11.Late Maastrichtian dinosaurs of the latest Cretaceous Phosphates of Morocco.
93mbeosaurines could have produced a high diversity of species in just a few million years.Few other assemblages have a comparably high diversity of lambeosaurines, the exception being the Dinosaur Park Formation of Alberta, which for a brief interval contained the genera Lambeosaurus, Corythosaurus, and Parasaurolophus93, but what is remarkable about Morocco is that it shows high diversity despite far more limited sampling, suggesting that it draws from a highly diverse fauna.