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Abstract and Figures
This research documents for the first time the detailed histological description of severe bone inflammation and the exceptional preservation of soft-bodied parasitical microorganisms inside the vascular canals of a non-avian dinosaur. The results bring new insights into the fields of parasitology, pathology, and histology in the fossil record. A senile titanosaur from the Upper Cretaceous of Southeast Brazil presented acute osteomyelitis, identified by the presence of a highly reactive periosteum with a filigree pattern, and localized dome-like cortical tissue inflammation connecting the former to the medulla. Furthermore, tens of parasites were identified throughout the specimen’s vascular canals. Novel histological insights resulted from the developmental description of an aggressive case of osteomyelitis. The lesions were either caused or facilitated by the parasitic infestation. This may be the earliest occurrence of infectious bone disease associated with parasites, adding new information to the complex biogeographic and evolutionary history of parasitic ailments.
... Hanna 2002;Farke et al. 2009;Peterson and Vittore 2012;Bell and Coria 2013;Tanke and Rothschild 2014;Foth et al. 2015;Bertozzo et al. 2017;, Garcia et al. 2017Xing et al. 2018;Haridy et al. 2019;Bastiaans et al. 2020;Pardo-Pérez et al. 2020). Evidence of disease and injury is detected mainly in the skeletal system, although some soft-tissue injuries can leave a signal in bone (Aureliano et al. 2020). An increasing list of palaeopathological lesions is reported for almost every clade of dinosaur, with particularly high frequencies noted in theropods (e.g., Molnar 2001;Bell and Coria 2013;Senter and Juengst 2016) and derived ornithopods (e.g., Rothschild et al. 2003;Tanke & Rothschild 2002;Tanke and Rothschild 2014;Siviero et al. 2020;Bertozzo et al. in prep.). ...
... In terms of non-avian dinosaurs, our record of paleopathology is limited. What we do know is that disorders such as trauma 23,30,31 , various forms of arthritis (such as spondyloarthropathy; 32 , neoplasia  , osteomyelitis 32 , vascular parasites 35 , and even transmissible diseases (such as trichomonosis 27 ) were present. ...
Other than repaired fractures, osteoarthritis, and periosteal reaction, the vertebrate fossil record has limited evidence of non-osseous diseases. This difficulty in paleontological diagnoses stems from (1) the inability to conduct medical testing, (2) soft-tissue pathologic structures are less likely to be preserved, and (3) many osseous lesions are not diagnostically specific. However, here reported for the first time is an avian-style respiratory disorder in a non-avian dinosaur. This sauropod presents irregular bony pathologic structures stemming from the pneumatic features in the cervical vertebrae. As sauropods show well-understood osteological correlates indicating that respiratory tissues were incorporated into the post-cranial skeleton, and thus likely had an ‘avian-style’ form of respiration, it is most parsimonious to identify these pathologic structures as stemming from a respiratory infection. Although several extant avian infections produce comparable symptoms, the most parsimonious is airsacculitis with associated osteomyelitis. From actinobacterial to fungal in origin, airsacculitis is an extremely prevalent respiratory disorder in birds today. While we cannot pinpoint the specific infectious agent that caused the airsacculitis, this diagnosis establishes the first fossil record of this disease. Additionally, it allows us increased insight into the medical disorders of dinosaurs from a phylogenetic perspective and understanding what maladies plagued the “fearfully great lizards”.
... At least three specimens of this new taxon are known from the same stratum, and detailed results and discussion out of the scope of this paper will be published separately along the description of this new taxon. One of the specimens, also senile, showed pathologies associated with acute osteomyelitis and preserved phosphatized blood parasites inside the vascular canals 31 . However, the specimen we analyze in this research showed signs of neither pathologies nor parasitization. ...
This study reports the occurrence of pneumosteum (osteohistological structure related to an avian-like air sac system) in a nanoid (5.7-m-long) saltasaurid titanosaur from Upper Cretaceous Brazil. We corroborate the hypothesis of the presence of an air sac system in titanosaurians based upon vertebral features identified through external observation and computed tomography. This is the fifth non-avian dinosaur taxon in which histological traces of air sacs have been found. We provided a detailed description of pneumatic structures from external osteology and CT scan data as a parameter for comparison with other taxa. The camellate pattern found in the vertebral centrum (ce) of this taxon and other titanosaurs shows distinct architectures. This might indicate whether cervical or lung diverticula pneumatized different elements. A cotylar internal plate of bone tissue sustains radial camellae (rad) in a condition similar to Alamosaurus and Saltasaurus . Moreover, circumferential chambers (cc) near the cotyle might be an example of convergence between diplodocoids and titanosaurs. Finally, we also register for the first time pneumatic foramina (fo) and fossae connecting camellate structures inside the neural canal in Titanosauria and the second published case in non-avian dinosaurs. The extreme pneumaticity observed in this nanoid titanosaur contrasts with previous assumptions that this feature correlates with the evolution of gigantic sizes in sauropodomorphs. This study reinforces that even small-bodied sauropod clades could present a hyperpneumatized postcranial skeleton, a character inherited from their large-bodied ancestors.
... They are, by definition, fields that are dedicated to study how elements related to geology and biology disciplines are present in cultural manifestations, therefore, being basic sciences instead of applied sciences. But it does not contradict our premise (to foster a holistic nature conservation and to achieve better geoconservation strategies) since we focus throughout this paper on how the basic principles gathered from these basic sciences are able to be applied to solve social issues in society, in the same manner paleontology is not a field of science dedicated to contribute to the advances in the medicine or the aeronautics fields, but its gathered information may have applications in both of them (e.g., Chatterjee et al. 2010;Roberts et al. 2011;Aureliano et al. 2021). ...
Nature conservation largely focuses on biological assets, treating geodiversity as a minor concern. We formally define here cultural geology, cultural biology, and cultural taxonomy, as emerging scientific fields focused on assessing the impact of natural sciences and natural features in the culture. We propose them as fundamental tools for innovative geoconservation strategies, since their integrated application provides a new pathway to achieve a holistic nature conservation, especially when combined with other areas as cultural paleontology and geomythology. These new fields can successfully assist in protecting geoheritage from a broader array of hazards. One of these potentials is to improve the scientist-population communication , leading to a more integrated perception of the geodiversity and biodiversity relevance as natural and cultural heritage, fostering an active role of the public in geoconservation approaches. However, as specified in this paper, these fields are not synonymous of science popularization or education. We also expect to show that adopting the Geoheritage wider definition of Ponciano et al. (Editora Interciência, Rio de Janeiro 4:853-869, 2011) is a better way of achieving the desired results in geoconservation. Finally, we propose that very influential geomyths and geodiversity-centered audiovisual products should be encompassed within an intangible geoheritage category, as a Ponciano et al.'s (Editora Interciência, Rio de Janeiro 4:853-869, 2011) ex situ geological heritage subset, in order to analyze the cultural impact of abiotic features in society under the heritage perspective.
... The paleopathological study of extinct species is the gateway to many, otherwise inaccessible, paleobiological traits such as intraspecific behavior (Farke et al., 2009;Peterson and Vittore, 2012;Peterson et al., 2013), diet and food acquisition (DePalma et al., 2013), etiology and healing capabilities Kato et al., 2020), soft tissue reconstruction (Rega et al., 2012), thermophysiology (Benoit et al., 2015), interspecific interactions (Aureliano et al., 2021), biting force (Erickson et al., 1996;Gignac et al., 2010), and even key transitional events in the evolutionary history of vertebrates such as the onset of arboreality in hominins and terrestriality in early tetrapods (Bishop et al., 2015;Kappelman et al., 2016). ...
Despite their significance for paleobiological interpretations, bite marks have been rarely reported in non-mammalian therapsids (NMT). Here we describe, for the first time, the occurrence of a tooth embedded in the snout of a gorgonopsian. The tooth is surrounded by a bony callus, which demonstrates that the animal was still alive after the attack and healed. The identity of the attacker is unknown. Two hypotheses are discussed to account for this healed bite: failed predation (most likely by a biarmosuchian, therocephalian, or another gorgonopsian) and intraspecific social biting. Though predation cannot be ruled out, it has been hypothesized that gorgonopsians used their saber-like teeth for social signaling, which suggests that social biting may be the most likely scenario. The practice of social biting has long been hypothesized in NMT, but this is the first fossilized evidence of the behavior to be described.
Parasitism is inherent to life and observed in all species. Extinct animals have been studied to understand what they looked like, where and how they lived, what they fed on, and the reasons they became extinct. Paleoparasitology helps to clarify these questions based on the study of the parasites and microorganisms that infected those animals, using as a source material coprolites, fossils in rock, tissue, bone, mummy, and amber, analyses of ancient DNA, immunodiagnosis, and microscopy.
In recent decades, intensive research on non-avian dinosaurs has strongly suggested that these animals were restricted to terrestrial environments1. Historical proposals that some groups, such as sauropods and hadrosaurs, lived in aquatic environments2,3 were abandoned decades ago4–6. It has recently been argued that at least some of the spinosaurids—an unusual group of large-bodied theropods of the Cretaceous era—were semi-aquatic7,8, but this idea has been challenged on anatomical, biomechanical and taphonomic grounds, and remains controversial9–11. Here we present unambiguous evidence for an aquatic propulsive structure in a dinosaur, the giant theropod Spinosaurus aegyptiacus7,12. This dinosaur has a tail with an unexpected and unique shape that consists of extremely tall neural spines and elongate chevrons, which forms a large, flexible fin-like organ capable of extensive lateral excursion. Using a robotic flapping apparatus to measure undulatory forces in physical models of different tail shapes, we show that the tail shape of Spinosaurus produces greater thrust and efficiency in water than the tail shapes of terrestrial dinosaurs and that these measures of performance are more comparable to those of extant aquatic vertebrates that use vertically expanded tails to generate forward propulsion while swimming. These results are consistent with the suite of adaptations for an aquatic lifestyle and piscivorous diet that have previously been documented for Spinosaurus7,13,14. Although developed to a lesser degree, aquatic adaptations are also found in other members of the spinosaurid clade15,16, which had a near-global distribution and a stratigraphic range of more than 50 million years14, pointing to a substantial invasion of aquatic environments by dinosaurs. Discovery that the giant theropod dinosaur Spinosaurus has a large flexible tail indicates that it was primarily aquatic and swam in a similar manner to extant tail-propelled aquatic vertebrates.
Plesiosaurs are a prominent group of Mesozoic marine reptiles, belonging to the more inclusive clades Pistosauroidea and Sauropterygia. In the Middle Triassic, the early pistosauroid ancestors of plesiosaurs left their ancestral coastal habitats and increasingly adapted to a life in the open ocean. This ecological shift was accompanied by profound changes in locomotion, sensory ecology and metabolism. However, investigations of physiological adaptations on the cellular level related to the pelagic lifestyle are lacking so far. Using vascular canal diameter, derived from osteohistological thin-sections, we show that inferred red blood cell size significantly increases in pistosauroids compared to more basal sauropterygians. This change appears to have occurred in conjunction with the dispersal to open marine environments, with cell size remaining consistently large in plesiosaurs. Enlarged red blood cells likely represent an adaptation of plesiosaurs repeated deep dives in the pelagic habitat and mirror conditions found in extant marine mammals and birds. Our results emphasize physiological aspects of adaptive convergence among fossil and extant marine amniotes and add to our current understanding of plesiosaur evolution.
In 2001, a nearly complete sub-adult Tenontosaurus tilletti was collected from the Antlers Formation (Aptian-Albian) of southeastern Oklahoma. Beyond its exceptional preservation, computed tomography (CT) and physical examination revealed this specimen has five pathological elements with four of the pathologies a result of trauma. Left pedal phalanx I-1 and left dorsal rib 10 are both fractured with extensive callus formation in the later stages of healing. Left dorsal rib 7 (L7) and right dorsal rib 10 (R10) exhibit impacted fractures compressed 26 mm and 24 mm, respectively. The fracture morphologies in L7 and R10 indicate this animal suffered a strong compressive force coincident with the long axis of the ribs. All three rib pathologies and the pathological left phalanx I-1 are consistent with injuries sustained in a fall. However, it is clear from the healing exhibited by these fractures that this individual survived the fall. In addition to traumatic fractures, left dorsal rib 10 and possibly left phalanx I-1 have a morphology consistent with post-traumatic infection in the form of osteomyelitis. The CT scans of left metacarpal IV revealed the presence of an abscess within the medullary cavity consistent with a subacute form of hematogenous osteomyelitis termed a Brodie abscess. This is only the second reported Brodie abscess in non-avian dinosaurs and the first documented occurrence in herbivorous dinosaurs. The presence of a Brodie abscess, known only in mammalian pathological literature, suggest mammalian descriptors for bone infection may be applicable to non-avian dinosaurs.
An absence of ancient archaeological and palaeontological evidence of pneumonia contrasts with its recognition in the more recent archaeological record. We document an apparent infection-mediated periosteal reaction affecting the dorsal ribs in a Middle Triassic eosauropterygian historically referred to as ‘Proneusticosaurus’ silesiacus. High-resolution X-ray microtomography and histological studies of the pathologically altered ribs revealed the presence of a continuous solid periosteal reaction with multiple superficial blebs (protrusions) on the visceral surfaces of several ribs. Increased vascularization and uneven lines of arrested growth document that the pathology was the result of a multi-seasonal disease. While visceral surface localization of this periosteal reaction represents the earliest identified evidence for pneumonia, the blebs may have an additional implication: they have only been previously recognized in humans with tuberculosis (TB). Along with this diagnosis is the presence of focal vertebral erosions, parsimoniously compared to vertebral manifestation of TB in humans.
In the last three decades, records of tribosphenidan mammalsfrom India, continental Africa, Madagascar and South Americahave challenged the notion of a strictly Laurasian distributionof the group during the Cretaceous. Here, we describe a lowerpremolar from the Late Cretaceous Adamantina Formation, SãoPaulo State, Brazil. It differs from all known fossil mammals,except for a putative eutherian from the same geologic unityandDeccanolestes hislopi, from the Maastrichtian of India. Theincompleteness of the material precludes narrowing downits taxonomic attribution further than Tribosphenida, butit is larger than most coeval mammals and shows a thinlayer of parallel crystallite enamel. The new taxon helpsfilling two major gaps in the fossil record: the paucity ofMesozoic mammals in more northern parts of South Americaand of tribosphenidans in the Cretaceous of that continent.In addition, high-precision U-Pb geochronology provided apost-Turonian maximal age (≤87.8 Ma) for the type stratum,which is overlain by the dinosaur-bearing Marília Formation, constraining the age of the Adamantina Formation at the site to late Coniacian–late Maastrichtian. This represents the first radioisotopic age for the Bauru Group, a key stratigraphic unit for the study of Cretaceous tetrapods in Gondwana.
We report an osseous abnormality on a specimen of the sauropod dinosaur Lufengosaurus huenei from the Fengjiahe Formation in Yuxi Basin, China. A gross pathological defect occurs on the right third rib, which was subjected to micro-computed tomographic imaging as an aid in diagnosis. The analysis of pathological characteristics and the shape of the abnormality is incompatible with impact or healed trauma, such as a common rib fracture, and instead suggests focal penetration of the rib, possibly due to a failed predator attack. The identification of characteristics based on gross morphology and internal micro-morphology presented by the specimen, suggests an abscess with osteomyelitis as the most parsimonious explanation. Osteomyelitis is a severe infection originating in the bone marrow, usually resulting from the introduction of pyogenic (pus-producing) bacteria into the bone. Micro-tomographic imaging of the lesion suggests a degree of healing and bone remodelling following post-traumatic wound infec
Osteomyelitis is reported for the first time in a sauropod dinosaur. The material
(MCS-PV 183) comes from the Anacleto Formation (Campanian, Late Cretaceous), at
the Cinco Saltos locality, R�ıo Negro Province, Argentina. The specimen consists of 16
mid and mid-distal caudal vertebrae of a titanosaur sauropod. Evidence of bacterial
infection is preserved in all of these vertebrae. The main anomalies are as follows:
irregular ‘microbubbly’ texture of bone surfaces produced by periosteal reactive bone,
abscesses on the rims of the anterior articular surfaces of two centra, numerous pits on
centra anterior articulation surfaces, erosions on the anterior articulation of the vertebral
centra, a vertical groove in posterior articular face of all the centra and disruption
of the prezygapophysis and postzygapophysis (mainly the articular face) from the vertebra
19 and beyond. The last anomaly is increasingly pronounced in more distal elements
of the series. Thin sections reveal that the anomalous cortical tissue is
composed of avascular and highly fibrous bone matrix. The fibres of the bone matrix
are organized into thick bundles oriented in different directions. Both morphological
and histological abnormalities in the MCS-PV 183 specimen are pathognomonic for
osteomyelitis. □ Histology, osteomyelitis, paleopathology, sauropoda, titanosauri
Bone abnormalities are common in theropod dinosaur skeletons, but before now no specimen was known with more than four afflicted bones of the pectoral girdle and/or forelimb. Here we describe the pathology of a specimen of the theropod dinosaur Dilophosaurus wetherilli with eight afflicted bones of the pectoral girdle and forelimb. On its left side the animal has a fractured scapula and radius and large fibriscesses in the ulna and the proximal thumb phalanx. On its right side the animal has abnormal torsion of the humeral shaft, bony tumors on the radius, a truncated distal articular surface of metacarpal III, and angular deformities of the first phalanx of the third finger. Healing and remodeling indicates that the animal survived for months and possibly years after its ailments began, but its right third finger was permanently deformed and lacked the capability of flexion. The deformities of the humerus and the right third finger may be due to developmental osteodysplasia, a condition known in extant birds but unreported in non-avian dinosaurs before now.
Osteopathy from derived hadrosauroids has been extensively studied. However, little work has been done
in the basal members of this group. Only two brief notes have recorded three examples of osteopathy
in the basal hadrosauroids in Bactrosaurus, Gilmoreosaurus and Jeyawati. In the present manuscript, we
found in the holotype of the basal hadrosauroid Huehuecanauhtlus tiquichensis (IGM 6253) from Mexico
two dorsal ribs and a dorsal vertebra with unusual pathologic conditions. The injuries are described as
possible premortem or perimortem anterior rib fracture, associated with a singular sclerosis and costovertebral
ankyloses which probably originated by spinal and rib osteomyelitis. The vertebral lesion caused
direct damage to the nervous system and possible back pain. This study represents the first study of
palaeopathology in a Mexican hadrosauroid in which the bone abnormalities are extensively compared
with previous studies and described in detail, their origins are interpreted, and the health implications for
the individual are considered.
Parasites are common in many ecosystems, yet because of their nature, they do not fossilise readily and are very rare in the geological record. This makes it challenging to study the evolutionary transition that led to the evolution of parasitism in different taxa. Most studies on the evolution of parasites are based on phylogenies of extant species that were constructed based on morphological and molecular data, but they give us an incomplete picture and offer little information on many important details of parasite-host interactions. The lack of fossil parasites also means we know very little about the roles that parasites played in ecosystems of the past even though it is known that parasites have significant influences on many ecosystems. The goal of this review is to bring attention to known fossils of parasites and parasitism, and provide a conceptual framework for how research on fossil parasites can develop in the future. Despite their rarity, there are some fossil parasites which have been described from different geological eras. These fossils include the free-living stage of parasites, parasites which became fossilised with their hosts, parasite eggs and propagules in coprolites, and traces of pathology inflicted by parasites on the host's body. Judging from the fossil record, while there were some parasite-host relationships which no longer exist in the present day, many parasite taxa which are known from the fossil record seem to have remained relatively unchanged in their general morphology and their patterns of host association over tens or even hundreds of millions of years. It also appears that major evolutionary and ecological transitions throughout the history of life on Earth coincided with the appearance of certain parasite taxa, as the appearance of new host groups also provided new niches for potential parasites. As such, fossil parasites can provide additional data regarding the ecology of their extinct hosts, since many parasites have specific life cycles and transmission modes which reflect certain aspects of the host's ecology. The study of fossil parasites can be conducted using existing techniques in palaeontology and palaeoecology, and microscopic examination of potential material such as coprolites may uncover more fossil evidence of parasitism. However, I also urge caution when interpreting fossils as examples of parasites or parasitism-induced traces. I point out a number of cases where parasitism has been spuriously attributed to some fossil specimens which, upon re-examination, display traits which are just as (if not more) likely to be found in free-living taxa. The study of parasite fossils can provide a more complete picture of the ecosystems and evolution of life throughout Earth's history.
We describe adaptations for a semiaquatic lifestyle in the dinosaur Spinosaurus aegyptiacus. These adaptations include retraction of the fleshy nostrils to a position near the mid-region of the skull and an elongate
neck and trunk that shift the center of body mass anterior to the knee joint. Unlike terrestrial theropods, the pelvic girdle
is downsized, the hindlimbs are short, and all of the limb bones are solid without an open medullary cavity, for buoyancy
control in water. The short, robust femur with hypertrophied flexor attachment and the low, flat-bottomed pedal claws are
consistent with aquatic foot-propelled locomotion. Surface striations and bone microstructure suggest that the dorsal “sail”
may have been enveloped in skin that functioned primarily for display on land and in water.
Remains of parasites in vertebrates are rare from the Mesozoic and Paleozoic. Once most parasites that live in - or pass through - the gastrointestinal tract of vertebrates, fossil feces (coprolites) or even intestinal contents (enterolites) can eventually preserve their remains. Here we announce the discovery of a spiral shark coprolite from the Paleozoic bearing a cluster of 93 small oval-elliptical smooth-shelled structures, interpreted as eggs of a tapeworm.The eggs were found in a thin section of an elasmobranch coprolite. Most of the eggs are filled by pyrite and some have a special polar swelling (operculum), suggesting they are non-erupted eggs. One of the eggs contains a probable developing larva. The eggs are approximately 145-155 µm in length and 88-100 µm in width and vary little in size within the cluster. The depositional and morphological features of the eggs closely resemble those of cestodes. Not only do the individual eggs have features of extant tapeworms, but their deposition all together in an elongate segment is typical to modern tapeworm eggs deposited in mature segments (proglottids). This is the earliest fossil record of tapeworm parasitism of vertebrates and establishes a timeline for the evolution of cestodes. This discovery shows that the fossil record of vertebrate intestinal parasites is much older than was hitherto known and that the interaction between tapeworms and vertebrates occurred at least since the Middle-Late Permian.
Long bones (femora, humeri) are the most abundant remains of sauropod dinosaurs. Their length is a good proxy for body length and body mass, and their histology is informative about ontogenetic age. Here we provide a comparative assessment of histologic changes in growth series of several sauropod taxa, including diplodocids (Apatosaurus, Diplodocus, indeterminate Diplodocinae from the Tendaguru Beds and from the Morrison Formation), basal macronarians (Camarasaurus, Brachiosaurus, Europasaurus), and titanosaurs (Phuwiangosaurus, Ampelosaurus). A total of 167 long bones, mainly humeri and femora, and 18 limb girdle bones were sampled. Sampling was performed by core drilling at prescribed locations at midshaft, and 13 histologic ontogenetic stages (HOS stages) were recognized. Because growth of all sauropod long bones is quite uniform, with laminar fibrolamellar bone being the dominant tissue, HOS stages could be recognized across taxa, although with minor differences. Histologic ontogenetic stages generally correlate closely with body size and thus provide a means to resolve important issue like the ontogenetic status of questionable specimens. We hypothesize that sexual maturity was attained at HOS-8, well before maximum size was attained, but we did not find sexually differentiated growth trajectories subsequent to HOS-8. On the basis of HOS stages, we detected two morphotypes in the Camarasaurus sample, a small one (type 1) and a larger one (type 2), presumably representing different species or sexual dimorphism.
For the past 25 years NIH Image and ImageJ software have been pioneers as open tools for the
analysis of scientific images. We discuss the origins, challenges and solutions of these two programs,
and how their history can serve to advise and inform other software projects.
Long bone histology of the most derived Sauropoda, the Titanosauria suggests that titanosaurian long bone histology differs from the uniform bone histology of basal Sauropoda. Here we describe the long bone histology of the titanosaur Ampelosaurus atacis and compare it to that of basal neosauropods and other titanosaurs to clarify if a special titanosaur bone histology exists.
Ampelosaurus retains the laminar vascular organization of basal Sauropoda, but throughout most of cortical growth, the scaffolding of the fibrolamellar bone, which usually is laid down as matrix of woven bone, is laid down as parallel-fibered or lamellar bone matrix instead. The remodeling process by secondary osteons is very extensive and overruns the periosteal bone deposition before skeletal maturity is reached. Thus, no EFS is identifiable. Compared to the atypical bone histology of Ampelosaurus, the large titanosaur Alamosaurus shows typical laminar fibrolamellar bone. The titanosaurs Phuwiangosaurus, Lirainosaurus, and Magyarosaurus, although differing in certain features, all show this same low amount or absence of woven bone from the scaffolding of the fibrolamellar bone, indicating a clear reduction in growth rate resulting in a higher bone tissue organization. To describe the peculiar primary cortical bone tissue of Phuwiangosaurus, Ampelosaurus, Lirainosaurus, and Magyarosaurus, we here introduce a new term, "modified laminar bone" (MLB).
Importantly, MLB is as yet not known from extant animals. At least in Lirainosaurus and Magyarosaurus the reduction of growth rate indicated by MLB is coupled with a drastic body size reduction and maybe also a reduction in metabolic rate, interpreted as a result of dwarfing on the European islands during the Late Cretaceous. Phuwiangosaurus and Ampelosaurus both show a similar reduction in growth rate but not in body size, possibly indicating also a reduced metabolic rate. The large titanosaur Alamosaurus, on the other hand, retained the plesiomorphic bone histology of basal neosauropods.
Amber fossils can be used to trace the history of disease-vector associations because microorganisms are preserved "in situ" inside the alimentary tract and body cavity of blood-sucking insects.
Lutzomyia adiketis sp. n. (Phlebotomidae: Diptera) is described from Dominican amber as a vector of Paleoleishmania neotropicum sp. n. (Kinetoplastida: Trypanosomatidae). The fossil sand fly differs from all previously described extinct and extant members of the genus by the following combination of characters: Sc forked with the branches meeting the costa and radius veins; wing L/W value of 4.1; a delta value of 18; a ratio beta/alpha value of 0.86, and the shape and size of the spatulate rods on the ninth sternite. The trypanosomatid is characterized by the structure of its promastigotes, amastigotes and paramastigotes and its transmission by an extinct species of sand fly.
Morphological characters show that the fossil sand fly is a new extinct species and that it is host to a digenetic species of trypanosomatid. This study provides the first fossil evidence that Neotropical sand flies were vectors of trypanosomatids in the mid-Tertiary (20-30 mya).
The diagnostic imaging of osteomyelitis can require the combination of diverse imaging techniques for an accurate diagnosis. Conventional radiography should always be the first imaging modality to start with, as it provides an overview of the anatomy and the pathologic conditions of the bone and soft tissues of the region of interest. Sonography is most useful in the diagnosis of fluid collections, periosteal involvement, and surrounding soft tissue abnormalities and may provide guidance for diagnostic or therapeutic aspiration, drainage, or tissue biopsy. Computed tomography scan can be a useful method to detect early osseous erosion and to document the presence of sequestrum, foreign body, or gas formation but generally is less sensitive than other modalities for the detection of bone infection. Magnetic resonance imaging is the most sensitive and most specific imaging modality for the detection of osteomyelitis and provides superb anatomic detail and more accurate information of the extent of the infectious process and soft tissues involved. Nuclear medicine imaging is particularly useful in identifying multifocal osseous involvement.
Sauropods were the largest terrestrial tetrapods (>10(5) kg) in Earth's history and grew at rates that rival those of extant mammals. Magyarosaurus dacus, a titanosaurian sauropod from the Upper Cretaceous (Maastrichtian) of Romania, is known exclusively from small individuals (<10(3) kg) and conflicts with the idea that all sauropods were massive. The diminutive M. dacus was a classical example of island dwarfism (phyletic nanism) in dinosaurs, but a recent study suggested that the small Romanian titanosaurs actually represent juveniles of a larger-bodied taxon. Here we present strong histological evidence that M. dacus was indeed a dwarf (phyletic nanoid). Bone histological analysis of an ontogenetic series of Magyarosaurus limb bones indicates that even the smallest Magyarosaurus specimens exhibit a bone microstructure identical to fully mature or old individuals of other sauropod taxa. Comparison of histologies with large-bodied sauropods suggests that Magyarosaurus had an extremely reduced growth rate, but had retained high basal metabolic rates typical for sauropods. The uniquely decreased growth rate and diminutive body size in Magyarosaurus were adaptations to life on a Cretaceous island and show that sauropod dinosaurs were not exempt from general ecological principles limiting body size.
Leptoconops nosopheris sp. n. (Diptera: Ceratopogonidae) is described from a blood-filled female biting midge in Early Cretaceous Burmese amber. The new species is characterized by a very elongate terminal flagellomere, elongate cerci, and an indistinct spur on the metatibia. This biting midge contained digenetic trypanosomes (Kinetoplastida: Trypanosomatidae) in its alimentary tract and salivary glands. These trypanosomes are described as Paleotrypanosoma burmanicus gen. n., sp. n., which represents the first fossil record of a Trypanosoma generic lineage.
A trypanosomatid (Trypanosomatidae: Kinetoplastida) associated with a blood-filled female sand fly in Cretaceous Burmese amber, is described in the new genus and species, Paleoleishmania proterus. The genus Paleoleishmania is established as a collective genus for digenetic fossil trypanosomes associated with sand flies. Amastigotes, promastigotes and paramastigotes are described. Paleoleishmania proterus is the first fossil kinetoplastid and provides a minimum age for the digenetic Trypanosomatidae. Its discovery indicates that vector-borne pathogens had been established by the Early Cretaceous.
A blood-filled sand fly, Palaeomyia burmitis, was recently described from Early Cretaceous Burmese amber. Within the alimentary canal of this sand fly were the amastigotes and promastigotes of a digenetic leishmanial trypanosomatid. Inside the lumen of the thoracic midgut of the fossil sand fly were nucleated blood cells, some of which were intact and others in various stages of lysis and disintegration. The present study identifies these blood cells as reptilian and describes putative developing amastigotes inside spherical to oval whitish vacuoles within some of the fossil blood cells. The significance of this find is discussed, especially regarding the high possibility that Cretaceous dinosaurs were infected by trypanosomatids.
Protozoan cysts and helminth eggs preserved in a coprolite from the Early Cretaceous Bernissart Iguanodon shaft in Belgium demonstrate that representatives of 3 phyla parasitized dinosaurs by that period. These fossil parasite stages are described and their possible effect on dinosaurs discussed. These findings represent the earliest fossil records of protozoan and helminth parasites of terrestrial vertebrates.
Titanosauria is a clade of sauropod dinosaurs that includes species ranging from the largest known terrest-rial vertebrates to insular dwarfs no bigger than elephants. Although most sauropod dinosaurs exhibit highly vascularized fibrolamellar bone signaling rapid growth rates comparable to those of extant mammals, diminutive titanosaurs apparently exhibit histological traits consistent with reduced primary growth rates and/or truncated active growth to reach small adult body sizes. A better understanding of the evolution of titanosaur body size requires additional sampling of the 40+ known titanosaur species. The best-preserved and most complete titanosaur yet discovered is Rapetosaurus krausei from the Maastrichtian Maevarano Formation in Madagascar. Skeletal material from many individuals spanning a wide range of ontogeny, from neonates to very large body sizes, makes Rapetosaurus an ideal candidate for an analysis of growth. We analyzed Rapetosaurus histology using a growth series of 25 forelimb, hind limb, and girdle elements representing different ontogenetic stages, including samples from the largest Rapetosaurus known (femur length = 143 cm). Primary bone histology in Rapetosaurus is highly vascularized fibrolamellar tissue, such as is found in other sauropods and most sampled titanosaurs. Secondary remodeling begins early, as noted in other titanosaur taxa, and by mid-ontogeny is pervasive in most sampled elements. The largest known Rapetosaurus was still growing, whereas some small juveniles exhibit an unusual pattern of bone erosion and replacement in the context of peripheral lines of arrested growth that signal a temporary pause in bone apposition. We hypothesize that these signals may relate to the drought-stressed ecosystem inhabited by Rapetosaurus.
Citation for this article: Curry Rogers, K., and Z. Kulik. 2018. Osteohistology of Rapetosaurus krausei (Sauropoda: Titanosauria) from the Upper Cretaceous of Madagascar. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2018.1493689.
The present study describes a primitive kissing bug (Hemiptera: Reduviidae: Triatominae) in mid-Cretaceous amber from northern Myanmar. The fossil, which is described as Paleotriatoma metaxytaxa gen. et sp. nov., contains a predominance of features of the Triatominae as well as some characters of the Reduviinae and is considered an intermediate fossil representing an early progenitor of the Triatominae. Based on the present distribution of the Triatominae and recent studies indicating that Burmese amber fossils could have originated in Gondwana, it is proposed that Paleotriatoma metaxytaxa is a Gondwanan lineage that evolved in the mid-Cretaceous. The specimen contains developing trypanosome flagellates in its hindgut, suggesting that early triatomines could have been vectoring pathogenic protozoa to vertebrates some 100 Ma.
Spinosaurinae are known to have a strong relationship with aquatic environments, involving several anatomical adaptations. Nonetheless, this group of theropods remains enigmatic, due to the relative incompleteness of its fossil record. A large partial tibia from the Aptian-Albian Romualdo Formation, Northeast Brazil, is herein described through anatomical comparisons and paleohistological analyzes. It features characteristics previously only observed in Spinosaurus aegyptiacus, which includes a reduced fibular crest and an osteosclerotic condition. The later, a character supported as correlated with semi-aquatic habits in many limbed vertebrates. The results presented here support high bone compactness being already present in Brazilian Spinosaurinae millions of years before the Moroccan Spinosaurus. Furthermore, histological analyses demonstrate the Romualdo Formation specimen was a young subadult still growing fast by the time of its death, and suggests Araripe Basin Spinosaurinae could have grown larger than previously thought. This work contributes to a better paleobiological and ecological understanding of South American spinosaurs, and helps fill a gap in the macroevolutionary comprehension of Spinosaurinae. Ultimately, it also contributes to further advancing the paleoecological characterization of the Romualdo Formation.
Vertebrate red blood cells (RBCs) display a range of sizes, spanning orders of magnitude in volume in different clades . The importance of this size variation to diffusion during exercise is reinforced by functional links between RBC and capillary diameters [2, 3]. Small RBCs, such as those of mammals (which lack nuclei) and birds, contribute to shorter diffusion distances and permit relatively fast O2 uptake kinetics . Although constraints on RBC size have been tied to the cell's need to attend capillary sizes for effective gas diffusion , as well as to genome size evolution [5, 6], major questions persist concerning patterns of RBC size evolution and its paleobiological significance. Here, we evaluate the relationship between RBC sizes and bone histometry and use microstructural evidence to trace their evolution in a phylogeny of extinct tetrapods. We find that several fossilizable aspects of bone microstructure, including the sizes of vascular and lacunar (cellular) spaces, provide useful indicators of RBC size in tetrapods. We also show that Triassic non-mammalian cynodonts had reduced and densely packed vascular canals identical to those of some mammals and likely accommodated smaller, more mammal-like RBCs. Reduced channel diameters accommodating smaller RBCs predated the origin of crown mammals by as much as 70 million years. This discovery offers a new proxy for the physiologic status of the mammal and avian stem groups and contextualizes the independent origins of their increased activity metabolism.
Here we describe a new record of a sauropod dinosaur from the Lower Cretaceous (Hauterivian-Barremian) Rio Piranhas Formation, Sousa Basin, NE Brazil. Dinosaur fossil bones from this deposit were
unknown until now. Thus, the discovery of a sauropod fibula from this locality is highly significant. Our
discovery represents an indeterminate titanosaur and the earliest stratigraphic occurrence of this group
in central Gondwana. When compared to chronocorrelate titanosaur trackmakers of this geological unit,
this fossil specimen appears substantially smaller. Histological analysis of the fibula suggests that this is a
relatively young individual (approximately 40-50% adult body size) that had passed its most rapid phase
of early juvenile growth, but had not yet attained somatic maturity. Thus, the fibula recovered is from a
young individual rather than from a small-bodied adult titanosaur.
The preservation of bone or bioapatite over geologic time has presented paleobiologists with long-standing and formidable questions. Namely, to elucidate the mechanisms, processes, rates, and depositional conditions responsible for the formation of a fossil from a once living tissue. Approaches integrating geochemistry, mineralogy, physics, hydrology, sedimentology, and taphonomy have all furthered insights into fossilization, but several fundamental gaps still remain. Notably, our limited understanding of: (1) the timing of processes during diagenesis (e.g., early and/or late), (2) the rate of bioapatite transformation into thermodynamically more stable phases, (3) the controls imparted by depositional environment, and (4) the role of (micro)biology in determining the fate of bone bioapatite (dissolution or preservation). The versatility of fossil bioapatite to provide information on the biology of extinct vertebrates rests on our ability to identify and characterize the changes that occurred to bioapatite during diagenesis. This review will evaluate our current understanding of bioapatite diagenesis and fossilization, focusing on the biogeochemical transformations that occur during diagenesis to the mineral and organic components of bone (excluding teeth and enamel), the analytical approaches applied to evaluate fossilization processes, and outline some suggestions for future promising directions.
The microscopic examination of fossilized bone tissue is a sophisticated and increasingly important analytical tool for understanding the life history of ancient organisms. This book provides an essential primer and manual for using fossil bone histology to investigate the biology of extinct tetrapods. Twelve experts summarize advances in the field over the past three decades, reviewing fundamental basics of bone microanatomy and physiology. Research specimen selection, thin-section preparation, and data analysis are addressed in detail. The authors also outline methods and issues in bone growth rate calculation and chronological age determination, as well as how to examine broader questions of behavior, ecology, and evolution by studying the microstructure of bone.
The occurrence of pyrite in fossil bone samples from different localities is studied by light microscopy. Two different mechanisms of pyrite precipitation are proposed to explain the observed characteristics of pyritization in fossil bone. One mechanism is the precipitation of dissolved ferrous ions by sulfide. This requires the release of sulfide from the decaying bone and/or reduction of sulfate to sulfide. Thus it is restricted to early diagenesis when decay of organic compounds in the bone still goes on. The second mechanism is the precipitation of iron sulfide due to a rise of the pH value. If a saturated solution of ferrous sulfide enters the bone, phosphate of the bone matrix buffers the pH to high values, leading to the precipitation of iron sulfide. This kind of pyrite formation is much slower than the first mechanism and occurs usually during late diagenesis.
Fossil deposits that preserve soft-bodied organisms provide critical evidence of the history of life. Usually, only more decay resistant materials, e.g., cuticles, survive as organic remains as a result of selective preservation and subsequent diagenesis to more resistant biopolymers. Permineralization, the permeation of tissues by mineralizing fluids, may preserve remarkable detail, particularly of plants. However, evidence of more labile tissues, e.g., muscle, normally requires the replication of their morphology by rapid in situ growth of minerals, i.e., authigenic mineralization. This process relies on the steep geochemical gradients generated by decay microbes. The minerals involved, and the level of detail preserved (which may be subcellular), depend on a number of factors, including the nature of microbial activity and amount of decay, availability of ions, and the type of organism that is fossilized. Understanding these controls is essential to determining the conditions that favor exceptional preservation.
A sub-adult Allosaurus fragilis (MOR 693) was discovered in 1991 in the Upper Jurassic Morrison Formation of Big Horn County, Wyoming. Examination of the specimen reveals pathological conditions on five dorsal ribs, gastralia, cervical vertebra, three dorsal vertebrae, caudal vertebra, chevron, scapula, manus phalanx, ilium, two metatarsals, and two pes phalanges. Detailed description of these bones includes classification according to probable cause (i.e., traumatic; infectious; traumatic-infectious; developmental; idiopathic). In addition to the paleopathological analysis of MOR 693, descriptions and interpretations are given from a study in progress of pathological abnormalities in the Cleveland-Lloyd Dinosaur Quarry collection. This study provides a model for future paleopathological analyses, emphasizing that description of the location, extent, and texture of an abnormality is crucial, since interpretations are subject to change.This analysis discusses physiological implications of the abnormalities in MOR 693 and suggests probable behaviors and environmental influences resulting in injury and infection. Lifestyle and behaviors that likely predisposed allosaurs to injury and infection include pursuit of prey, intra-specific competition for mates, and intra- and inter-specific rivalry for carcasses and territory. Ultimately, paleopathological analysis of a large sample of dinosaur bones may reveal that certain abnormalities characterize taxa, and are diagnostic of specific behaviors, environmental influences, and physiology.
Fossil bones (N = 350) spanning more than 350 million years, and covering a wide range of depositional environments, were studied to compare the distribution of microbial destruction features in fossil bones with previously published data sets of bones of archaeological age. The distribution of bioerosion in fossil bones is very different from that found in bone from archaeological sites. Fossil bones typically show little or no bioerosion. Under normal conditions, if a bone is to survive into the fossil record, then rapid bioerosion must be prevented (or halted). This conclusion suggests that early post mortem processes,such as the mode of death, influence the potential of any bone to survive into deep time.
Quantitative analysis has tremendous but mostly unrealized potential in healthcare to support objective and accurate interpretation of the clinical imaging. In 2008, the National Cancer Institute began building the Quantitative Imaging Network (QIN) initiative with the goal of advancing quantitative imaging in the context of personalized therapy and evaluation of treatment response. Computerized analysis is an important component contributing to reproducibility and efficiency of the quantitative imaging techniques. The success of quantitative imaging is contingent on robust analysis methods and software tools to bring these methods from bench to bedside.
Osteonecrosis is a common disorder that may go clinically unrecognized or may result in the collapse of the architecture of bone, determining severe anatomic alterations of the involved site. Osteonecrosis is not a specific disease entity, but rather the result of a number of conditions ultimately leading to an impairment of blood supply to the bone tissue, although there is evidence that modifications of bone remodelling activity and weakening of bone structure with formation of microfractures are implicated as well. According to the site involved and to the factors promoting its development, the morbid anatomy and histopathology of osteonecrosis show a different appearance. This review discusses the main skeletal manifestations of osteonecrosis, including subarticular avascular necrosis of the femoral head and of the knee, as well as osteonecrosis of the jaw.
Whale fossils from a variety of geologic ages and depositional environments were thin-sectioned and analyzed for evidence of microbial activity, comprising a combination of microborings, authigenic pyrite, botryoidal cements, and micropeloids. Borings are dense in some samples with an average diameter of 8.02 µm. Framboidal pyrite crystals with an average diameter of 61.84 µm in diameter occur within the pore spaces of the bone, in borings, and at the bone–sediment interface. The pyrite crystals are densely packed at the edges of the bone and scattered more randomly throughout the pore spaces. Aragonitic botryoidal cements line pore spaces in samples from deep bathyal settings. Potential bacterial peloids occur within pore spaces with an average size of 77.45 µm or diffuse to comprise clotted micrite. Since bacterial body fossils are extremely rare in the fossil record, recognition of past microbial ecosystems must be based on multiple lines of supporting evidence. Of the independent signatures studied, the bacterial peloids and botryoids provide the most convincing evidence of a sulfophilic stage. These fossil biosignatures suggest that a sulfophilic stage is preserved at least as far back as the Eocene.
The incidence of chronic osteomyelitis is increasing because of the prevalence of predisposing conditions such as diabetes mellitus and peripheral vascular disease. The increased availability of sensitive imaging tests, such as magnetic resonance imaging and bone scintigraphy, has improved diagnostic accuracy and the ability to characterize the infection. Plain radiography is a useful initial investigation to identify alternative diagnoses and potential complications. Direct sampling of the wound for culture and antimicrobial sensitivity is essential to target treatment. The increased incidence of methicillin-resistant Staphylococcus aureus osteomyelitis complicates antibiotic selection. Surgical debridement is usually necessary in chronic cases. The recurrence rate remains high despite surgical intervention and long-term antibiotic therapy. Acute hematogenous osteomyelitis in children typically can be treated with a four-week course of antibiotics. In adults, the duration of antibiotic treatment for chronic osteomyelitis is typically several weeks longer. In both situations, however, empiric antibiotic coverage for S. aureus is indicated.
Acute osteomyelitis is the clinical term for a new infection in bone. This infection occurs predominantly in children and is often seeded hematogenously. In adults, osteomyelitis is usually a subacute or chronic infection that develops secondary to an open injury to bone and surrounding soft tissue. The specific organism isolated in bacterial osteomyelitis is often associated with the age of the patient or a common clinical scenario (i.e., trauma or recent surgery). Staphylococcus aureus is implicated in most patients with acute hematogenous osteomyelitis. Staphylococcus epidermidis, S. aureus, Pseudomonas aeruginosa, Serratia marcescens and Escherichia coli are commonly isolated in patients with chronic osteomyelitis. For optimal results, antibiotic therapy must be started early, with antimicrobial agents administered parenterally for at least four to six weeks. Treatment generally involves evaluation, staging, determination of microbial etiology and susceptibilities, antimicrobial therapy and, if necessary, debridement, dead-space management and stabilization of bone.
Parasites are characterized by their fitness-reducing effect on their hosts. Studying the evolution of parasitic diseases is an attempt to understand these negative effects as an adaptation of the parasite, the host, both or neither. Dieter Ebert and E. Allen Herre here discuss how the underlying concepts are general and are applicable for all types of disease-producing organisms, broadly defined here as parasites. The evolutionary processes that lead to the maintenance of the harmful effects are believed to be characterized by genetic correlations with other fitness components of the parasite. Depending on the shape of these correlations, any level of virulence can evolve.
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