Gastroliths Research Articles

A Nearly Complete Skeleton of the Fossil Galliform Bird Palaeortyx from the Late Oligocene of Germany

Phasianid galliform birds do not occur in Europe before the end of the early Oligocene, and their Paleogene fossil record mainly comprises isolated bones. Here we describe a nearly complete and articulated skeleton of a phasianid galliform bird from the late Oligocene of Enspel in Germany. The specimen is assigned to Palaeortyx cf. gallica Milne-Edwards, 1869 and for the first time allows the recognition of cranial and pelvic details in a late Oligocene phasianid. Many gizzard stones are preserved in both the gizzard and the crop, and constitute the earliest fossil evidence for grit use in a phasianid galliform.

The first corydalid larva (Megaloptera: Corydalidae) with gut-contents from the Early Cretaceous Jehol biota of northeastern China

The fossil record of the family Corydalidae (Megaloptera) is rare with only six reported species and several undescribed larvae from the Middle Jurassic to Eocene. Little is known about the food habits and digestive system of ancient insects. We report the first corydalid larva preserved with gut contents from the Lower Cretaceous Yixian Formation of northeast China, examining the contents using a scanning electron microscope with energy dispersive X-ray analysis. The results show that the main component of the gut contents is quartz gastroliths ('stomach stones'), providing the first fossil evidence of a gastric mill promoting digestion in a megalopteran larva, extending the record of this behaviour to the Early Cretaceous.

Crayfish gastroliths

Crayfish produce small button‐like gastroliths in their stomachs. These curious calcitic objects are increasingly common in lakes and streams in the UK and Europe as the invasive American crayfish increase their domination of freshwater environments. These stomach stones are also present in the geological record.

The trophic habits of early birds

Although direct associations that reveal diet are extremely rare in the fossil record, the rich Lower Cretaceous Jehol Lagerstätte has produced dozens of specimens preserving ingested items, which together reveal important information regarding the early evolution of the avian alimentary canal. Direct evidence indicates Jeholornis and Sapeornis ate seeds and like living granivores utilized a gastric mill although only the more derived Sapeornis possessed a crop for food storage. Despite their smaller numbers in the Early Cretaceous, most direct evidence pertains to the Ornithuromorpha, indicating a structurally and functionally modern alimentary canal was present in even the earliest members of this clade. Similar evidence is altogether lacking in the Enantiornithes suggesting this clade was characterized by a primitive alimentary canal, potentially factoring into the ultimate extinction of this successful Cretaceous lineage. The role of the gizzard in the loss of teeth in Aves is more complex than in non-avian theropod lineages. As in neornithines, the presence of gastroliths in basal ornithuromorphs may not be entirely indicative of herbivory although this diet does appear to correlate with complete tooth loss in this clade. Positive selection for specialized tooth morphologies persists throughout the evolution of Aves and in the Ornithuromorpha appears to be linked to piscivory. Although represented by the greatest numbers, no direct indicator of diet preference is preserved in any confuciusornithiform or enantiornithine suggesting these clades utilized different nutritional strategies. The absence of teeth and gastroliths in all confuciusornithiforms suggest this lineage may have secondarily switched to a non-herbivorous, soft diet. Similarly, the absence of gizzard stones in enantiornithines also suggests a soft diet while their small body size suggests Early Cretaceous species would have fed on invertebrates. The diversity of recognized dental patterns including enamel specializations observed in Jehol enantiornithines suggests effective resource partitioning of available invertebrate faunas and that teeth had an active participation in enantiornithine feeding strategies.

First report of gastroliths in the Early Cretaceous basal bird Jeholornis

Seeds preserved in association with the holotype of Jeholornis prima provided the first direct evidence of granivory in any Mesozoic bird. Although this long boney-tailed bird also displays several morphological indicators correlated with herbivory such as reduced dentition and a deep mandible, Jeholornis has not been previously reported to possess a gastric mill. However, this feature is commonly linked to herbivory in theropod dinosaurs and present in at least one sympatric ornithuromorph and the basal pygostylian Sapeornis, which also preserve direct evidence of granivory. Here we describe gastrolith masses preserved in five specimens of Jeholornis. The cluster of gizzard stones is nearly identical in each specimen, consisting of a tightly associated mass of proportionately small stones. Three previously undescribed specimens preserving seeds are also identified. Unlike in Sapeornis and a previously described ornithuromorph, no specimen of Jeholornis preserves both seeds and gastroliths. This may be due to the fact that, unlike in other Early Cretaceous birds, the seeds preserved in specimens of Jeholornis are found in the abdomen, suggesting that Jeholornis may have resembled extant ratites in lacking an esophageal crop. Consistent differences in the preservation and morphology of the gastrolith mass between Jeholornis and other early birds hint at subtle variations in alimentary function among basal lineages. Differences in ingested seed morphology among taxa in turn suggest these functional variations may be at least partially related to differences in diet.

On the composition of gastroliths from broiler breeders.

The purpose of this study was to ascertain the composition and origin of certain gastroliths or gizzard stones from broiler breeders (Gallus gallus domesticus). Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction techniques were used as analysis tools. The main components resulted to be organic fibre and minerals referred to a pegmatite rock (quartz, feldspar albite and haematite) used as grit. Although the generally accepted purpose of gastroliths in chicken is the crushing and grinding of foodstuff in the ventriculus, the importance of mineral uptake from grit of iron and other essential elements such as Al, Ca, K, Cl, P, Ti, Mn, Mg, Cu, Zn and Zr (in ppm) as a secondary effect of the abrasion and dissolution of gastroliths should not be disregarded.

An ethno-pharmacological study of plants used for traditional medication in Tangail district, Bangladesh.

BackgroundIn Bangladesh, folk medicinal practitioners are called “Kaviraj” and are consulted for treatment of various ailments by a large part of the rural and urban population. There are some previous studies conducted in the Tangail district of Bangladesh about medicinal plants, but there is no relevant information about this aspect in some parts of this district.AimTo conduct an ethno-pharmacological survey among the “Kaviraj” of two upazilas (regions) in Tangail district, namely Tangail Sadar Upazila and Nagarpur Upazila, to identify the trouble-free formulations of medicinal plants for various diseases used by the folk medicine practitioners on or after other forms of medical practices.MethodsA guided field-walk survey was carried out employing a local guide and asking local people about practicing “Kaviraj”; four of the “Kaviraj” convened and after receiving permission from the “Kaviraj”, interviews were conducted through focused group discussion.ResultsIt was observed that the “Kaviraj” of the two upazilas used a total of 25 plants distributed into 20 families for healing of various diseases. In most of the cases, leaves were the key part of most of the plants used for treatment. Plants were mainly used for treating gastrointestinal tract disorders, fever, constipation, and diarrhea, and indigestion, loss of appetite, pain and skin disorders. “Kaviraj” also treat complicated diseases such as tuberculosis, hypertension, sexual disorders, infections, urinary problems, hepatic disorders, pneumonia, stomach stones, diabetes, swellings, debility, kidney problems, tumor, vitamin C deficiency and poisoning by using medicinal plantsConclusionFor a country such as Bangladesh, and particularly the district studied, medicinal plants are essential assets and have a major role in people’s health care structure. Also, appropriate research should be conducted for using these medicinal plants in possible new drug designs as well as many other pharmaceutical benefits.

内蒙古鄂尔多斯早白垩世甲龙类胃石与鳞片印痕化石的发现

内蒙古鄂尔多斯盆地北部早白垩世志丹群陆相沉积中产有丰富的脊椎动物化石，其中包含兽脚类、剑龙类和鹦鹉嘴龙类等恐龙类群。1件不完整的甲龙类化石最近发现于杭锦旗老龙豁子罗汉洞组中，该化石保存有一团胃石以及局部鳞片印痕。至少22枚坚硬且磨圆度较好的砾石保存在联合荐椎和左肠骨前方，砾石长径为20 mm至35 mm，显示该甲龙类大体呈原位保存的胃石的存在。在颈椎附近露出有面积约为40 cm2的鳞片印痕，单个鳞片基本上呈四边形、相互不接触不叠覆，面积多在6 mm2与12 mm2之间。该标本不仅代表了鄂尔多斯盆地早白垩世甲龙类化石的首次发现，也是我国第1例保存有胃石与鳞片印痕的甲龙类化石，在研究甲龙类的生态习性方面等具有较为重要的科学价值。 The Early Cretaceous terrestrial Zhidan Group of the Ordos Basin, Inner Mongolia produced ab-undant fossil vertebrates including several dinosaur groups such as theropods, stegosaurs and psittacosaurids. Recently, an incomplete ankylosaur skeleton has been found from the Luohandong Formation at Laolonghuozi site, Hangjin Qi. Fortunately, a cluster of gastroliths and some area of scale impressions are clearly preserved. At least 22 pebbles are presented at the position just ahead of synsacrum. They are hard and rounded, with each pebble roughly 20 millimeters to 35 millimeters in long axis. These pebbles should be interpreted as gastroliths (stomach stones). More than 40 square centimeters of scale impressions are exposed near the cervical vertebrae. Each scale is generally trapezoid in outline, with the area varying from 6 square millimeters to 12 square millimeters. These scales are small and separate, compared with the relatively large and various shaped osteoderms in ankylosaurs. This specimen represents not only the first finding of ankylosaur dinosaurs among the Early Cretaceous vertebrate fauna in Ordos Basin, but also the first example of the ankylosaur gastroliths and scale impressions in China.

The rarity of gastroliths in sauropod dinosaurs – a case study in the Late Jurassic Morrison Formation, western USA

Abstract. Occurrences of suspected sauropod geo-gastroliths and "exoliths" (exotic clasts) are compared with authentic finds of stomach stones in the sauropods Diplodocus, Cedarosaurus, and Camarasaurus. Sedimentological and taphonomical evidence from classic sauropod dinosaur localities in the Late Jurassic Morrison Formation (Cleveland-Lloyd Dinosaur Quarry, Dry Mesa Dinosaur Quarry, Carnegie Quarry/Dinosaur National Monument, Howe Quarry, Como Bluff, and Bone Cabin Quarry) reveals very few sauropod finds with unambiguous gastroliths. The scarcity of clasts in the fine-grained sediments of most of the localities suggests that only a small number of sauropods possessed gastroliths. The occurrence of a hypothetical avian-style gastric mill in sauropods is not supported by taphonomical evidence. Exoliths that are abundant in the Early Cretaceous of the western USA are nearly absent in Late Jurassic sediments. Without an association with fossil bone, there is no convincing evidence that such clasts represent former gastroliths. It is more plausible that most exoliths have been transported in hyperclastic flows or that surface-collected stones are weathering relicts of former conglomerate layers.

Deadly Gastroliths: Eurasian SiskinsCarduelis spinusPoisoned by Road Salt Grains

We describe a case of winter mass mortality of Eurasian Siskins Carduelis spinus caused by large road salt grains that birds apparently had mistaken for potential gizzard stones (gastroliths). Clinical evidence revealed acute salt intoxication as the cause of death. We recommend using only small-sized salt grains (<2 mm) for de-icing roads in order to save wintering birdlife from a potentially hazardous substance.

A new specimen of large-bodied basal Enantiornithine Bohaiornis from the Early Cretaceous of China and the inference of feeding ecology in Mesozoic birds

A new specimen of Bohaiornis guoi from the Jiufotang Formation, comprising a nearly complete skeleton, sheds light on enantiornithine morphological variation and ecological specialization. The new specimen was collected from near Lamadong Village in Liaoning Province, which is the same area where the sub-adult holotype specimen was reported. It provides new information on the cranial and pectoral girdle anatomy of the species, e.g., broad nasal, strikingly robust acromion, medially curved acrocoracoid process. In contrast to the holotype, the newly referred specimen has small rounded stones in the thoracic region that in other extinct taxa has been interpreted as direct evidence of diet. Direct evidence of diet is so far unknown in other Enantiornithes. Specifically the lack of “stomach stones” or gastroliths in enantiornithines despite their excellent fossil record has been proposed to be related to their insectivorous diet as well as to their arboreal ecology. We hypothesize that cranial morphology as well as the number and shape of the preserved stones in Bohaiornis may be most consistent with a raptorial ecology previously unknown for Enantiornithes and considered rare for Avialae. While rostrum shape has a strong relationship to feeding ecology in living birds, in basal avialan birds most diversity is in dental morphology, number, and distribution of the teeth.

First occurrence of stomach stones in pterosaurs

ABSTRACT Two nearly complete skeletons of the filter-feeding pterodactyloid Pterodaustro guinazui from the Lower Cretaceous of Argentina exhibit clusters of poorly sorted coarse sand to fine gravel inside the abdominal cavity. These stones are interpreted as ingested gastroliths (geogastroliths), which are commonly found in a variety of archosaurs (including birds) but have never before been reported in a pterosaur. The geogastroliths found in these Pterodaustro specimens are interpreted as having assisted in the digestion of hard food items such as ‘shelled’ crustaceans that are abundant in the fossil beds of this pterosaur. One of these specimens with geogastroliths has anterior mandibular teeth that are notably thicker than the posterior teeth and are somewhat procumbent. We suggest that these teeth might have facilitated the apprehension of fine gravel.

Why birds eat colourful grit: colour preferences revealed by the colour of gizzard stones

Colour preferences from sexual or social contexts are assumed to have arisen owing to preferences for specific kinds of food, representing a sensory bias, but once colour preferences have evolved in a sexual context, they may also be expressed during foraging. We tested whether preferences for specific body colours (i.e. plumage and soft parts) were related to colour preferences for grit ingested by birds. Birds eat grit to facilitate break down of food by the gizzard, and this function is independent of the colour of grit, but depends on the physical properties of stones. Bird species were significantly consistent in colour of grit, and grit of different colours varied in prevalence among species, even when analyses were restricted to a sample from a single locality. There were positive correlations between presence of lilac and red grit in the gizzard and presence of sexually dichromatic lilac and red colour on the body. There was a positive correlation between red grit colour and red sexually monochromatic body colour. Bird species with many different sexual colours, but not sexually monochromatic colours on their body had many different colours of grit. Males had more lilac and red grit than females, with this effect differing among species, whereas that was not the case for grit of other colours. These findings are consistent with the sensory bias hypothesis that birds express preferences for grit of specific colours and a high diversity of colours related to sexual colouration of the body, even when the colour of such grit is only visible to the individual at the moment of ingestion.

Unusual occurrence of gastroliths in a polycotylid plesiosaur from the Upper Cretaceous Tropic Shale, southern Utah

A polycotylid plesiosaur (Dolichorhynchops sp.), recently discovered in the Upper Cretaceous (Cenomanian-Turonian) Tropic Shale in Glen Canyon National Recreation Area, southern Utah, is associated with 289 gastroliths. This specimen is significant due to the general lack of gastroliths associated with most short-necked plesiosaur skeletons. The skeleton (MNA V10046) was excavated from a stratigraphic interval of marine shale that does not contain coarser-grained material. The stones were generally concentrated in one area of the skeleton, with the majority situated near the back of the skull. The stones are mainly composed of dark grey chert, are smooth and well rounded, and have varying degrees of polish. The majority of the stones are spherical in shape and are likely fluvial in origin. The gastroliths from this animal are similar in shape and number to those documented from elasmosaurid plesiosaurs. The gastroliths from MNA V10046, however, are much smaller and weigh considerably less than most elasmosaurid stomach stones. Given the lack of comparative material from other short-necked plesiosaurs, the size and mass differences are attributed to differences in function of gastroliths between long- and short-necked plesiosaurs.

Gastroliths in An Ornithopod Dinosaur

Gastroliths (stomach stones) are known from many extant and extinct vertebrates, including dinosaurs. Reported here is the first unambiguous record of gastroliths in an ornithopod dinosaur. Clusters of small stones found in the abdominal region of three articulated skeletons of Gasparinisaura cincosaltensis were identified as gastroliths on the basis of taphonomic and sedimentologic evidence. The large number of stones found in each individual, their size, and the fact that Gasparinisaura cincosaltensis was herbivorous, all suggest that they were ingested as a result of lithophagy rather than accidental swallowing.

Recognition of Paleogastroliths from the Lower Cretaceous Cedar Mountain Formation, Utah using a Scanning Electron Microscope

Paleogastroliths, as defined in this study, are stomach stones associated exclusively with extinct animals. Definitive recognition of paleogastroliths is problematic and controversial. Polished, rounded stones found within skeletal remains of dinosaurs and plesiosaurs are the strongest evidence. This study examined intraskeletal and proposed paleogastroliths using a scanning electron microscope (SEM) to determine if any defining surface textures occur. Paleogastroliths associated with the skeletal remains of Seismosaurus hallorum, possible paleogastroliths from the Lower Cretaceous Cedar Mountain Formation, and other well-polished stones were obtained. Most stones were composed of either quartzite or chert and were examined with a SEM at magnifications ranging from 100× to 400×. All of the cherty Seismosaurus hallorum stones contained sets of parallel to sub-parallel, curved polish grooves that in places crosscut one another. These grooves are inferred to have formed as the result of small particles lodged in the stomach muscles interacting with the stones due to muscle movement. The distinctive surface textures noted on the cherty Seismosaurus hallorum paleogastroliths are similar to those seen on the cherty possible paleogastroliths from the Cedar Mountain Formation. Therefore, the geologic occurrence combined with the microscopic surface texture supports the interpretation that these stones are paleogastroliths.

No gastric mill in sauropod dinosaurs: new evidence from analysis of gastrolith mass and function in ostriches

Polished pebbles occasionally found within skeletons of giant herbivorous sauropod dinosaurs are very likely to be gastroliths (stomach stones). Here, we show that based on feeding experiments with ostriches and comparative data for relative gastrolith mass in birds, sauropod gastroliths do not represent the remains of an avian-style gastric mill. Feeding experiments with farm ostriches showed that bird gastroliths experience fast abrasion in the gizzard and do not develop a polish. Relative gastrolith mass in sauropods (gastrolith mass much less than 0.1% of body mass) is at least an order of magnitude less than that in ostriches and other herbivorous birds (gastrolith mass approximates 1% of body mass), also arguing against the presence of a gastric mill in sauropods. Sauropod dinosaurs possibly compensated for their limited oral processing and gastric trituration capabilities by greatly increasing food retention time in the digestive system. Gastrolith clusters of some derived theropod dinosaurs (oviraptorosaurs and ornithomimosaurs) compare well with those of birds, suggesting that the gastric mill evolved in the avian stem lineage.

A beaked basal ornithurine bird (Aves, Ornithurae) from the Lower Cretaceous of China

We report here one of the earliest known beaked ornithurine birds from the Lower Cretaceous deposits in Liaoning, northeast China. The new basal ornithurine, Archaeorhynchus spathula gen. et sp. nov., has a rhynchokinetic skull with toothless jaws. It also contains over three dozen preserved gizzard stones, suggesting an herbivorous diet. The distal end of the tibiotarsus is unfused, enabling recognition of the astragalus with a broad ascending process, generally similar to that of Archaeopteryx. The new discovery sheds new light on our understanding of the early radiation and diet diversification of early birds in the Lower Cretaceous.

GASTROLITHS IN THE TRIASSIC ICHTHYOSAUR PANJIANGSAURUS FROM CHINA

Gastroliths (stomach stones) are frequently reported in association with plesiosaur remains, especially elasmosaurids (e.g., Brown, 1904; Williston, 1904; Welles and Bump, 1949; Darby and Ojakangas, 1980; Everhart, 2000; Cicimurri and Everhart, 2001). Stones are also known from several other fossil and modern aquatic vertebrates, including fishes (Dapples, 1938; Thomson, 1966; Trewin, 1986), penguins (Emery, 1963; Stonehouse, 1967; Boswall and MacIver, 1975), crocodilians (Cott, 1961; Neill, 1971; Keller and Schaal, 1992), and pinnipeds (Fleming, 1951; Mohr, 1963; Bryden, 1999). However, gastroliths are very rarely reported in ichthyosaurs, despite the fact that a large number of articulated skeletons are known from this clade. Some ichthyosaurs show preserved gut contents (e.g., Pollard, 1968; Keller, 1976; Kear et al., 2003), and sand is occasionally found in the gastric area of ichthyosaurs (R. Wild, personal commun., 2000; Wings, personal obs.). Gastroliths with grain sizes >2 mm are only known from two specimens: the one described in detail here and a complete but undescribed skeleton from the famous Upper Jurassic Solnhofen Limestone of Germany (Taylor, 1993; Wings, personal observation). The German specimen is probably referable to the genus Nannopterygius Huene, 1922, so far only known from England. The specimen is preserved as a slab, which is on exhibit at the Jura-Museum, Eichstatt, Germany, and a counterslab, which is accessioned to the collections of the Staatliches Museum fur Naturkunde, Karlsruhe, Germany. A description of the stones found in the perfect holotype specimen (Museum of the Yichang Institute of Geology and Mineral Resources # T1) of Panjiangsaurus epicharis described by Chen and Cheng (2003) (Fig. 1) is important not only because of the scarcity of ichthyosaurian gastroliths, the find is also relevant for the interpretation of gastrolith function. Panjiangsaurus epicharis …

A case of gastroliths

A case of gastroliths