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The nests of Cadeguala albopilosa (Spinola, 1851), Diphaglossa gayi Spinola, 1851, Ptiloglossa tarsata (Friese, 1900), Ptiloglossa matutina (Schrottky, 1904) and Zikanapis tucumana (Moure, 1945) (Colletidae, Diphaglossinae) from Argentina and Chile are described herein. They show similar features to those of other Diphaglossinae: they consist of a main tunnel, cells disposed radially, isolated or in pairs, and connected to the main tunnel by laterals ones. Main tunnels are mostly vertical in species nesting in soil surface but horizontal to inclined in D. gayi, which nests in banks. Cells are vertical with curved necks. The cells of C. albopilosa show less curved necks (less than 90°), whereas in the remaining four species the cell neck is highly curved (90° or more). Cells of P. tarsata have a spiral earthen closure and a wad cottonlike material, whereas in P. matutina only had the last one. In the remaining studied species any type of closure were found. Cocoons of C. albopilosa and P. tarsata are coriaceous showing a closure composed of three disks. Zikanapis tucumana and possibly P. matutina showed dim-light foraging. The remaining species are diurnal. The climate in their nesting sites is highly diverse, ranging from 8°C to 20°C in mean annual temperature, and from 250 mm to 3000 mm in mean annual precipitation. Only C. albopilosa and, to a lesser extent, Z. tucumana nested gregariously. Zikanapis tucumana and P. tarsata were observed visiting flowers of Solanum. [ABSTRACT FROM AUTHOR]

Abstract: The possible producer and environmental setting of large meniscate burrows (Nagtuichnus meuleni igen. and isp. nov.) occurring in late Miocene and Holocene aeolian deposits from Argentina are discussed. These are unbranched burrows with an uniform meniscate filling that range in width from 46 to 78mm. N. meuleni distinguishing features are a filling composed of a discontinuous, outer massive layer between a central meniscate core and the excavation boundary, sets of parallel ridges in the external wall, and a particular outline plus the presence of paired pits in the concave surface of menisci (or hollows in the convex surface). The late Miocene lower member of the Río Negro Formation at La Lobería (Río Negro province) is interpreted as aeolian dune, damp interdune and dry interdune deposits. The Holocene sediments from Gran Salitral (southwestern La Pampa province) represent aeolian dune, wet interdune and dry interdune deposits. N. meuleni occurs only in damp and dry interdune deposits. The composite ichnofabric produced by N. meuleni in the Holocene of the Gran Salitral is composed of two suites of trace fossils. A former Skolithos suite includes Skolithos linearis, Taenidium barretti, Polykladichnus aragonensis and root traces developed in lacustrine calcareous mudstone deposits (wet interdune). This suite is overprinted by N. meuleni, with subordinate participation of S. linearis and root traces, composing the Nagtuichnus suite. The later suite is developed in brown silt and sand of dry interdune areas. The Nagtuichnus ichnofabric is considered indicative of damp to dry interdune facies of late Miocene to Holocene age. The burrow systems of the likely producers of the Holocene N. meuleni structures were studied in the field and in the laboratory. The candidates were selected from the extant local fauna of the Gran Salitral, including southern cavies (Microcavia australis, Rodentia), tuco-tucos (Ctenomys azarae, Rodentia), and pink fairy armadillos or pichiciegos (Chlamyphorus truncatus, Xenarthra). The most likely producer of N. meuleni are pichiciegos because they have fully subterranean habits and insectivorous diet involving the production of long, unbranched, horizontal burrows excavated in sand, which are mostly backfilled. In contrast to this, tuco-tucos and southern cavies, which are herbivores that forage aboveground, use their more permanent burrows for dwelling and reproduction. As observed in a live, captive-kept C. truncatus, the meniscate structure of the fill can be explained by the animal packing the excavated sand with its rump plate. This mechanism also results in a massive layer of sediment in the burrow fill. Other significant bioglyphs that are a sort of fingerprint of pichiciegos are the outline of menisci in cross-section (mimicking their rump plate) and pairs of rounded pits in the concave surface of menisci (probably tail traces). [Copyright &y& Elsevier]

The article focuses on the predation of a solitary bee nests of Centris muralis by the mammal Zaedyus pichiy. It says that observations were made from November 24-20, 2008 in Vinchina, La Rioja province in Argentina, wherein the bee nests occupied most of the plowed area. Results show that predation of the nests was dominant at first glance because of high density of mammal excavations. It adds that the mammals' liking for C. muralis nests is due to the loose soil and the high density of nests.

Abstract: This study includes three aspects: 1) the ichnotaxonomic treatment of large and dominantly vertical burrows ornamented with sharp bioglyphs from the fluvial Neogene Vinchina and Toro Negro formations (northwest Argentina); 2) the description and interpretation of the sedimentary facies where these burrows occur; and 3) neoichnologic observations on large ornamented burrows from seasonal wetlands of the Río Pilcomayo National Park (Argentina) as possible modern analogues of the trace fossils and the sedimentary environment. A new ichnogenus and ichnospecies, Capayanichnus vinchinensis, is proposed to include the large striated burrows. The new ichnotaxon is distinguished by a combination of a predominantly vertical orientation, overall “L” shape (when fully developed), absence of lining and burrow bifurcation, a distinct surface texture, and lack of burrow enlargements. The hosting sedimentary facies of the Vinchina Formation can be grouped into fluvial channel and splay (floodplain) facies associations. The rivers of that unit were of two main types: single channel rivers with frequent channel avulsion and overbank flow and multichannelised rivers with poorly defined margins. At least some of these rivers were ephemeral or with intermittent discharge. The climate was probably seasonal and semiarid, as suggested by sedimentologic evidence. C. vinchinensis was dominantly recorded from the top of fluvial channels (interpreted as abandoned channels) and proximal, intermediate and distal splay facies. The large ornamented burrows found in an extant comparable example were constructed by freshwater crabs. These burrows can be distinguished by the overall architecture, the taxonomy and sex of its occupants, and the environmental setting where they were found. The neoichnologic signatures used in the interpretation of the fossil example include the common oval burrow cross-section and the surface texture. In particular, the surface texture in the modern crab burrows includes abundant comma-shaped marks, sets of grooves oblique to burrow axis, and long segmented grooves. The predominantly oval cross-section, absence of lining, and the strongly ornamented burrow surface suggest that C. vinchinensis was produced by freshwater crabs. The key features of the surface ornament are long sets of three–four ridges whose width is in average one third of the burrow major axis. Other features that also point to a crab origin are a massive filling, common burrow ends in a casing mudstone, chevron pattern in sets of surface ridges, and possible cheliped marks. The new ichnotaxon is restricted, in the Vinchina and Toro Negro formations, to fluvial facies and is absent in shallow lacustrine facies. [Copyright &y& Elsevier]

Abstract: The purpose of this study is to apply neoichnological observations to the behavioural and taphonomic interpretation of a Late Triassic–Early Jurassic track surface from the Santo Domingo Formation (Argentina) containing hundreds of bird-like tracks and trackways. In addition, the factors affecting the formation and preservation of bird tracks in lacustrine settings are particularly addressed. The 5.5 m2 fossil track surface contains different types of trace fossils: the avian ichnotaxa Gruipeda dominguensis (the most abundant), bird-like tracks with elongated hallux impressions, small epichnial rounded pits, and invertebrate traces (Skolithos, Taenidium). The modern environmental analogue chosen for the neoichnological studies was a coastal freshwater pond (the Bajo de los Huesos, Chubut, Argentina) seasonally occupied by sandpipers (Calidris bairdii and Calidris fuscicollis; Charadriiformes). The comparison between the fossil succession and the modern example suggests that they share lithology and sedimentary structures and that sedimentary processes and local palaeoenvironment were fairly similar and do not bias ichnological comparisons. Field observations allowed to distinguish twenty one behaviours that produced distinct traces and four modern footprint types (1 to 4) related to specific substrate conditions. In particular, the preferential formation of bird tracks parallel to the waterline, also confirmed by studies on droppings and invertebrate fauna of the pond, and other associated sedimentary features (ripple marks, wrinkle marks, mud drape thickness) and trace fossils were important for recognition of the shoreline in the fossil example. These observations also allowed us to distinguish the adjacent deeper and shallower parts of the fossil pond and can be applicable to other similar case studies. Contrasting sediment properties and footprint types, some relationships and constraints on the formation and preservation of modern footprints are proposed; although these are very complex processes that will require further studies. Five of the behaviours recognised in the modern pond were inferred from the sixteen trackways distinguished on the fossil track surface, including walking, walking with a zig-zag path, short runs, probing, and landing with legs directed forward (possible trace of flight). The recognition of traces of flight (Volichnia), probing marks, and tracks showing morphology similar to modern shorebirds (G. dominguensis), strongly suggest an avian affinity for the producers of the fossil tracks and, in consequence, the Santo Domingo track site would be younger than supposed. [Copyright &y& Elsevier]

The ichnospecies Phagophytichnus pseudocircus isp. nov. is described to include trace fossils characterized by leaf-margin excisions showing eccentricity values of 0.35–0.65 and more than 270 degrees of an arc, a non cuspate margin and vein stringers or necrotic flaps of tissue along the margin. A method for determining ellipse eccentricity was performed on leaf discs obtained from the nests of the modern leafcutter bee Megachile rotundata (Hymenoptera: Megachilidae), which provided objectively obtained values comparable to the trace fossil from the middle Eocene of Argentina and other world-wide ichnological records, historically and subjectively considered to be ‘circular’ trace fossils and attributed to leafcutter bees. The material described herein represents the first evidence for fossil Megachilidae from the Southern Hemisphere. [ABSTRACT FROM AUTHOR]

Hemispherical pan or dish-shaped trace fossils from the Cenozoic of the Central Patagonia are attributed to the burrowing action of cicadas. A new ichnotaxon, Feoichnus challa igen. et isp. nov. is characterized by its hemispherical shape, mostly subvertical orientation, smoothed internal lining showing knobbly surface texture, and rough and irregular external surface devoid of ornamentation. The wall is composed of a lining plus a layer of soil material consolidated passively by cicada excretions. In other specimens the wall shows a repetition of linings and soil layers reflecting changes in the position of the chambers. Grooves, which represent traces of roots originally related to the feeding activities of cicada nymphs, are located in the wall of many specimens of F. challa. These grooves are subvertical to subhorizontal and show smooth surfaces with longitudinal striations. The cicadan origin of these traces is supported by comparison of the fossils to modern cicada nymph chambers and by laboratory experiments. The most significant characters that emerged from the comparison are the differential preservation of the basal part of the chambers, the interior lining with similar surface texture, and the presence of root traces in the wall and in the interior of the chamber. Additional records of F. challa from the Cretaceous–Pliocene of the USA, the Oligocene of Ethiopia, and the Miocene of the United Arab Emirates and Kenya complete the current information yielded by the known body fossil record to help understand the evolutionary history of cicadas. [ABSTRACT FROM AUTHOR]

Abstract: Three new records of insect pupation chambers are reported from two localities in the Cretaceous Chubut Group of Patagonia, Argentina: from Sierra Nevada, a new and older ichnospecies of Rebuffoichnus, R. sciuttoi isp. nov. (Coprinisphaeridae), and the first Cretaceous and South American specimens of Pallichnus dakotensis Retallack (Pallichnidae), known until now from a single North American Oligocene locality; from Cañadón Puerta del Diablo, a new type of Rebuffoichnus casamiquelai Roselli that shows some differences from known material of the ichnospecies from the same locality, suggesting a different trace maker. Affinities of P. dakotensis, interpreted originally as a cast of a lined pupation chamber, remain unknown in the light of the new material. Its micromorphology is quite simple, with no constructed wall. R. sciuttoi has a very thinly constructed wall, showing an external texture composed of lobes and fine, helically arranged ridges. Such characters are compatible with those of wasp cocoons. R. casamiquelai, interpreted originally as a coleopteran pupation chamber, has a thickly constructed wall composed of two layers of soil material, showing redistribution of clay and orientation of long grains. Macro- and micromorphology of palaeosols indicate that in both localities pupation occurred in vitric entisols developed on pyroclastic ash-fall deposits on a fluvial floodplain. These new records double the number of the few Cretaceous insect pupation chambers. This is a critical period for understanding the origin and early evolution of building behaviour in insects. Three types of Cretaceous pupation chambers can now be recognized: (1) excavated and lined, e.g. Fictovichnus and Pallichnus (Pallichnidae); (2) constructed mostly with silk, resulting in thin-walled cocoons, e.g. R. sciuttoi (Coprinisphaeridae); (3) constructed mostly with soil material, resulting in thick-walled chambers, e.g., R. casamiquelai (Coprinisphaeridae). A new ethological category, Pupichnia, is proposed for grouping ichnotaxa representing pupation chambers, which, with Calichnia representing nests, comprises the two major types of insect trace fossils in palaeosols. [Copyright &y& Elsevier]

Describes bird-like footprints from a Late Triassic redbed sequence of Argentina. Anatomy of birds; Measurements of the footprints; Differences in the characteristics of footprints of avian and non-avian theropods.

Genise, J.F. & Farina, J.L. 2011: Ants and xenarthrans involved in a Quaternary food web from Argentina as reflected by their fossil nests and palaeocaves. Lethaia, Vol. 45, pp. 411-422. Quaternary (Ensenadan stage-age) deposits of the Miramar Formation from the Buenos Aires sea coast near Mar del Plata (Argentina) are well known for bearing long horizontal tunnels produced by xenarthrans, either ground sloths or armadillos. Little known is that, in some cases, these palaeocaves cross-cut social insect nests. Nests of two studied palaeocaves can be attributed to ants based on the presence of abundant ant remains, filling of chambers and organic-rich linings. Insect remains show part of a food web composed of army ants ( Neivamyrmex) preying on leaf-cutting ants ( Acromyrmex), Pheidole and other soil invertebrates. The other main component of this web is represented by the xenarthrans feeding on these ants. The facultative foraging function of xenarthran palaeocaves is supported by the common record of these extended horizontal tunnel systems similar to other subterranean foraging mammals, the presence of insect nests cross-cut by them and the extended myrmecophagy among xenarthrans. Xenarthran foraging burrows, despite their high-energy cost, would have been favoured by abundance of underground ant nests during Quaternary times and harsh climate. This climate would have produced the scarcity of insects on surface and longest periods of underground activity by xenarthrans, involving the extension of shelter burrows for adult and possibly juvenile feeding. □ Ant fossil nests, Argentina, Buenos Aires, food web, Quaternary, xenarthran palaeocaves. [ABSTRACT FROM AUTHOR]

Abstract: The analysis of the total number of phytoliths, and the absolute frequencies of the different morphotypes, extracted from fossil dung beetle brood balls (Coprinisphaera) from the Middle Eocene–Early Miocene Sarmiento Formation (Patagonia, Argentina), revealed that this trace fossil represents a concentrated locus for phytolith sampling. Particularly, differences found in the total number of phytoliths among parts of that trace fossil and the bearing paleosol, allowed to infer that the infilling represents mostly a sample of the original surrounding soil, whereas in most cases the wall shows a significantly higher number of phytoliths than in the paleosol or infilling. Modern brood balls also revealed that in an environment with high density of grasses, the walls, composed of soil and dung fibres, showed a lower concentration of phytoliths than the soil. In contrast, in other environment with scarce grass coverage, the dung, which had a higher concentration of phytoliths than the soil, added to the wall produced an increase in the number of phytoliths in it. Accordingly, the larger number of phytoliths of the Coprinisphaera wall in comparison with that of the paleosol, would be reflecting the addition of dung fibres to the wall in palaeoenvironments with moderate to poor presence of phytolith-bearing plants. The absence of differences in the total number of phytoliths between the internal and the external layer of the brood ball wall, suggests that the dung fibres would have been uniformly distributed in most of the wall, due to the addition of dung fibres during the brood ball construction by the dung beetle. In contrast, the absence of differences among wall and paleosol or infilling, could be suggesting that no dung fibres were added to construct the wall, that those added had no phytoliths, that the Coprinisphaera involved could had been a brood ball of a necrophagous scarab, or that the soils were richer in phytoltihs than the dung. Those balls that showed evidence of increased numbers of phytoliths in the wall, likely caused by dung fibres added to it, enable the study of diet preferences of the herbivores that produced the dung. Differences found in the phytolith morphotype frequencies among the wall, and the other two samples (infilling and paleosol), allow to infer that some herbivores were more generalists among phytolith-bearing plants feeding on the most abundant grasses and palms, whereas others preferred more rare grasses and dicots. [Copyright &y& Elsevier]

Abstract: Late Jurassic–Early Cretaceous volcaniclastic continental deposits from central Patagonia, Argentina were analyzed for an integral characterization of palaeosol ichnofabrics. These units contain complex continental ichnofabrics that were also recorded in other late Jurassic–late Miocene extended volcaniclastic successions from Patagonia. According to a recently proposed method, ichnofabric, pedofabric and original bedding of selected intervals were measured separately in order to determinate the degree in which the deposits are affected by soil features besides the ichnofabrics. Four recurrent ichnofabrics were recognized in studied palaeosols: the Loloichnus, large Taenidium–Beaconites, diffuse boxwork, and Dagnichnus ichnofabrics. The Loloichnus ichnofabric is characterized by sub-vertical Loloichnus baqueroensis and subordinate, similarly arrenged large Taenidium barretti and Beaconites coronus. L. baqueroensis is a crayfish dwelling structure while large T. barretti and B. coronus are assigned to locomotion of the same organisms. Root traces are additional components of this ichnofabric. The large Taenidium–Beaconites ichnofabric is formed by large, irregular and curved T. barretti and B. coronus and by L. baqueroensis in low proportion. This ichnofabric is also assigned to crayfish activity. The diffuse boxwork ichnofabric is characterized by a pervasive and intricate three-dimensional boxwork of burrows; occasionally joined to subspherical chambers (possible Castrichnus). The diffuse boxwork is interpreted as an earthworm burrow system and the associated chambers are probably for aestivation. Rare and scattered discrete trace fossils in this ichnofabric include L. baqueroensis, T. barretti and B. coronus. The Dagnichnus ichnofabric is formed by Dagnichnus titoi, root traces and, subordinately, Loloichnus baqueroensis, Cellicalichnus meniscatus and tangled groups of meniscate burrows. D. titoi and C. meniscatus has been interpreted as crayfish breeding structures and the tangled groups of meniscate burrows are probably related to juvenile crayfish activity. The studied ichnofabrics were formed in weakly to moderately developed palaeosols in lowland areas with frequent reworking of pyroclastic material by unconfined flows. The recognized ichnofabrics show that in Patagonia, for the Late Jurassic–Early Cretaceous times, crayfishes and earthworms were the dominant soil organisms and, along with plants, rapidly colonized deposits exposed subaerially. After sediment deposition and with high soil moisture content or high water table crayfishes probably crawled in moist sediments forming the large Taenidium–Beaconites ichnofabric. With a better drained soil profile or lower water tables, the Loloichnus ichnofabric, representing the dwelling structures of adult crayfishes, overprinted the previous ichnofabric. The diffuse boxwork ichnofabric, usually located in the uppermost portion of palaeosols, correspond to extensive fossil earthworm burrow systems. The Dagnichnus ichnofabric occurs in very weakly developed palaeosols and probably reflects the optimal palaeoenvironmental conditions for breeding crayfish. [Copyright &y& Elsevier]

Abstract: The known ichnospecies of Coprinisphaera have been usually linked to dung beetles of coprophagous habits living in grass-dominated environments inhabited by large herbivorous, which provide the dung for constructing brood balls. A new ichnospecies consisting of bispherical and thin-walled structures, Coprinisphaera akatanka, is separated from the pear-shaped and thick-walled structures that remains in C. tonni. C. akatanka consists of an egg chamber separated from the provision chamber by a deep neck. This morphology is comparable with brood balls constructed by extant species of Canthon showing necrophagous habits. This similarity suggests that the producers of C. akatanka might also display necrophagous feeding habits. The new bispherical structures were found in Sanandresian Aridisols (Early Pleistocene) developed in loess deposits of the Pampean region. Such paleosols record stable floodplains, covered with herbaceous and shrubby vegetation, under a seasonal, semiarid temperate-cold climate during a phase of glacier expansion in Patagonia. Sanandresian Land Mammal Substage shows a sparse record of large herbivorous, potential producers of suitable pads for dung beetles; only Neuryurus sp. and Glossotherium sp. are recorded in the area. The extinction of autochtonous taxa associated to palaeoenvironmental stress conditions during the Sanandresian Substage and the absence of the allochtonous taxa involved in Great American Biotic Interchange produced a bottleneck for dung availability. Such scenario of reduced dung resources would have favored dung beetle necrophagy in the Pampean region reflected herein with C. akatanka record. [Copyright &y& Elsevier]

Abstract: Dung beetles use the dung of herbivores, particularly large mammals, to provision their underground nests in which they construct brood balls where the egg is laid. These insects are usually linked to grass-dominated habitats (GDH) inhabited by abundant and large mammals, which, feeding on grasses, produce large amounts of the insects'' food: dung. Fossil brood balls of dung beetles, included in the ichnogenus Coprinisphaera, are typical trace fossils of Southern South American Cenozoic palaeosols. This ichnogenus includes five ichnospecies, C. murguiai, C. isp. A, C. kheprii, C. tonnii, and C. kraglievichi, all of which are represented in a pyroclastic fluvial and loessic (eolian) sequence of the middle Eocene-lower Miocene Sarmiento Formation at the classic palaeontological locality of Gran Barranca (Chubut, Argentina). This locality bears a detailed litho and chronostratigraphic framework that is based on several sedimentologic and magnetostratigraphic profiles and numerous radiometric ages. These provide a high-resolution stratigraphy for tracking the changes in dung beetle faunas as reflected in their trace fossils, and accordingly, to record the evolution of GDH. Particular objectives are to analyze: 1) the first Coprinisphaera records; 2) the increase in Coprinisphaera size and its relationship to mammal size; 3) the relative sizes of ichnospecies of Coprinisphaera to infer the potential dung beetle diversity; and (4) the major changes in the evolution of GDH as reflected by dung beetle trace fossils. About 1200 specimens of Coprinisphaera belonging to the five ichnospecies and to 15 statigraphical levels were collected, sectioned, identified, and measured. The parameters statistically analyzed were: relative abundance of ichnospecies, density of specimens per m2, and equatorial diameter (ED). From this analysis it was possible to recognize several episodes in the evolution of dung beetle faunas and the associated GDH of southern South America. The first episode, by the late middle Eocene (39.8Ma), records a favorable palaeoenvironmental change that achieved the critical point to support a GDH suitable for the appearance of the first dung beetles. This episode finishes with the total absence of dung beetle traces due to arid conditions. The second episode, by the early late Eocene (approximately 37.3Ma), records a burst in the density, abundance, and diversity of Coprinisphaera and dung beetles favored probably by the settlement of GDH with large herbivores. This episode concluded near the Eocene–Oligocene transition, with another xeric period without Coprinisphaera records. During the early late Oligocene (approximately 26Ma), the third episode shows similar parameters than the second one recording the return to the optimal palaeoenvironmental conditions of the second episode. The fourth episode (approximately 24.7Ma), during the middle late Oligocene, reflects changes within a relatively stable ecosystem, recording a significant increase in Coprinisphaera size, along with the disappearance of the smallest specimens, triggered by the appearance of large to huge herbivores. During the Oligocene–Miocene transition, the fifth episode (24.2–20.4Ma) records stability in palaeoenvironmental conditions, suggested by similar parameters to those of the previous episode. During the middle early Miocene (approximately 19.8Ma), the sixth episode records unfavorable environmental changes for dung beetles and GDH at Gran Barranca. This episode records the first evidence of a deterioration of the dung beetle fauna. From the latest early Miocene onward (19.3–18.7Ma), there is no more evidence of Coprinisphaera, suggesting unfavorable environmental conditions that led to the disappearance of dung beetles from the area of the Gran Barranca. [Copyright &y& Elsevier]

We document evidence of endophytic oviposition on fossil compression/impression leaves from the early Eocene Laguna del Hunco and middle Eocene Río Pichileufú floras of Patagonia, Argentina. Based on distinctive morphologies and damage patterns of elongate, ovoid, lens-, or teardrop-shaped scars in the leaves, we assign this insect damage to the ichnogenus Paleoovoidus, consisting of an existing ichnospecies, P. rectus, and two new ichnospecies, P. arcuatum and P. bifurcatus. In P. rectus, the scars are characteristically arranged in linear rows along the midvein; in P. bifurcatus, scars are distributed in double rows along the midvein and parallel to secondary veins; and in P. arcuatuin, scars are deployed in rectilinear and arcuate rows. In some cases, the narrow, angulate end of individual scars bear a darkened region encompassing a circular hole or similar feature indicating ovipositor tissue penetration. A comparison to the structure and surface patten of modern ovipositional damage on dicotyledonous leaves suggests considerable similarity to certain zygopteran Odonata. Specifically, members of the Lestidae probably produced P. rectus and P. bifurcatus, whereas species of Coenagrionidae were responsible for P. arcuatum. Both Patagonian localities represent an elevated diversity of potential fern,gymnosperm, and especially angiosperm hosts, the targets of all observed oviposition. However, we did not detect targeting of particular plant families. Our results indicate behavioral stasis for the three ovipositional patterns for at least 50 million years. Nevertheless, synonymy of these oviposition patterns with mid-Mesozoic ichnosDecies indicates older origins for these distinctive modes of ovinosition [ABSTRACT FROM AUTHOR]