The genus Sarcocystis comprises apicomplexan parasites associated with clinical manifestations, including reproductive and neurological disorders, in a wide range of domestic and wild animals. Infections by Sarcocystis spp. have been reported in birds on all continents except Antarctica. In this context, the present study reports two cases in which Sarcocystis spp. were identified at different developmental stages, endogenous and exogenous, in wild birds captured in Southeastern Brazil. Oocysts and sporocysts were detected in the feces of a roadside hawk Rupornis magnirostris, captured on Marambaia Island, Rio de Janeiro State, Brazil. In addition, bradyzoite cysts were observed in the muscle tissue of a rufous-bellied thrush Turdus rufiventris, captured in Itatiaia National Park. Accordingly, this study provides comments on the parasitic dynamics of Sarcocystis spp. in a wild environment and discusses the potential species involved in these host-parasite associations. For Sarcocystis sp. detected in the rufous-bellied thrush, based on evidence from previous studies, we strongly suggest that this species is Sarcocystis falcatula. In contrast, for Sarcocystis sp. detected from the roadside hawk, no specific species assignment can be made, as data on hawks acting as definitive hosts of Sarcocystis spp. in South America remain scarce. Although S. falcatula may involve Accipitriformes in its life cycle, members of this order are considered intermediate rather than definitive hosts for this species. Therefore, we present herein a survey of Sarcocystis spp. that involve Accipitriformes in their life cycles, including comparative data on sporocyst measurements for each species.

The diversity of coccidians in Neotropical wild avifauna remains significantly underestimated, particularly within the family Hirundinidae. While cosmopolitan and widely distributed hosts like Hirundo rustica Linnaeus, 1758 dominate the literature with three described Isospora spp., ecological traits of other swallows may drive different parasitic dynamics. This study provides the first integrative characterization of a coccidian parasite from Atticora tibialis (Cassin, 1853), a resident swallow strictly associated with complex and preserved Neotropical forest biomes. Fecal samples were collected from three White-Thighed Swallows, A. tibialis, captured using mist nets in the Itatiaia National Park, Southeastern Brazil, during field expeditions in 2023 and 2024. Oocysts were processed through standard flotation and morphological analyses. Molecular characterization was performed by extracting genomic DNA from isolated oocysts and sequencing of a locus of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. Phylogenetic trees were reconstructed using Bayesian Inference and Maximum Likelihood. One bird was positive for coccidia (33.3

Black-goggled tanagers Trichothraupis melanops (Vieillot, 1818) are passerine birds commonly observed in the Brazilian Atlantic Forest, Argentina and Paraguay. Tanagers are among the passerines with the highest prevalence and density of coccidian parasites, mainly due to their frugivorous feeding habits that favor fecal-oral transmission. In this context, the current study identifies a new species of Isospora Schneider, 1881 parasitizing black-goggled tanagers captured in the Itatiaia National Park, a protected area with a high degree of vulnerability in Southeastern Brazil. The oocysts of Isospora tiedetopetei Almeida-Berto & Berto n. sp. are subspheroidal to ovoidal, measuring on average 24 by 23 μm. Micropyle is absent. Oocyst residuum absent, but comma-like and splinter-like polar granules are present. Sporocysts are ovoidal to slightly pear-shaped, measuring on average 16 by 11 μm. Stieda and sub-Stieda bodies are present. Sporocyst residuum is present among the vermiform sporozoites, which have striations, refractile body and nucleus. This morphology was different from the other Isospora spp. recorded in the same subfamily as the host. Molecular identification was targeted by the amplification and sequencing of four loci of the mitochondrial genome and the small subunit ribosomal RNA (18S) gene. In molecular and phylogenetic analyses of concatenated sequences of 5 fragments, I. tiedetopetei n. sp. sat in monophyly and/or had high similarities with Isospora spp. from passerines. Finally, based on the morphological and molecular analyses of the oocysts recovered from black-goggled tanagers T. melanops in the current study, I. tiedetopetei n. sp. is established new to science, being the seventh species recorded in the host subfamily Tachyphoninae and the first to have a molecular characterization based on mitochondrial genes and the nuclear 18S gene.

Coccidiosis of domestic chickens is caused by seven Eimeria species, in addition to three recently proposed species: Eimeria lata, Eimeria nagambie, and Eimeria zaria. This study reports the first identification of E. lata in domestic chickens in Brazil, the successful establishment of a pure E. lata isolate, and its morphological and molecular analyses. Fecal samples were collected from six extensive production systems in the state of São Paulo, Brazil, and screened for the 10 Eimeria species of domestic chickens through species-specific PCRs. To obtain E. lata oocysts, a mixture of oocysts from various Eimeria species was sequentially administered to commercial broiler chickens vaccinated against coccidiosis. Subsequently, a pure isolate of E. lata was obtained by micromanipulation and propagated in chickens. Eimeria lata oocysts were further subjected to morphological and molecular characterization. In conclusion, these findings constitute the first documentation of E. lata in domestic chickens in Brazil. The Brazilian E. lata isolate, designated BR-AMC, exhibited molecular and morphological characteristics similar to those of E. lata isolates from other countries.

Tyzzeria Allen, 1936 is a coccidian genus traditionally associated with Anseriformes, although there are descriptions of Tyzzeria spp. from junglefowls, snakes, skinks and mice. In this sense, the current study performs a taxonomic review of Tyzzeria spp., evaluating those that should be valid, invalid or that require further studies for validation. Along with this review, oocysts morphologically identified as Tyzzeria parvula (Kotlán, 1933) Klimeš, 1963 were recovered from fecal samples of swan geese Anser cygnoid (Linnaeus, 1758) in the mountainous region of the State of Rio de Janeiro, which were molecularly identified through the sequencing of a locus of the small subunit ribosomal RNA (18S) gene, providing the first deposit of the genus Tyzzeria in GenBank. Finally, this sequence of T. parvula prompted a broad phylogenetic analysis covering species of the main chromist taxa, which evidenced homoplasies associated with taxonomic characters of gametogony, basic oocyst configuration and excystation structures; in addition to positioning T. parvula in a monophyletic group within the order Eimeriida together with Schellackia spp., Eimeria spp. and Caryospora-like spp. from reptiles and amphibians.

Catharus fuscescens (Stephens, 1817), Veery, is a Nearctic-Tropical migrant that winters mainly in Brazilian Amazonia and Cerrado. In the Atlantic Forest of the southeastern region of Brazil, it is frequently recorded in S & atilde;o Paulo and Minas Gerais states, but remains undocumented from Rio de Janeiro. We report the first confirmed record of C. fuscescens in Rio de Janeiro, based on a banded specimen (F7817) captured on Marambaia Island, Mangaratiba. This finding contributes to the understanding of the species' distribution and migratory routes and supports conservation strategies in southeastern Brazil.

ABSTRACTWe describe and characterize a new Isospora species from the Singing honeyeater (Gavicalis virescens) in Western Australia, both morphologically and molecularly. Microscopic analysis of a fecal sample identified 25 ellipsoidal oocysts, measuring 21–25 × 18–20 μm (mean 23.4 × 18.7 μm), with a length/width (L/W) ratio of 1.2–1.3 (mean 1.25). The oocyst wall is bilayered and ~1.0 μm thick, with a smooth outer layer making up about two‐thirds of the thickness. A micropyle cap, measuring ~2.0 × 4.5 μm, is present as a curved protrusion on the outer layer. The micropyle itself is ~4.5 μm wide. The oocysts lack a residuum but contain 1–2 polar granules. The 25 ellipsoidal sporocysts measured 14–15 × 8–9 μm (mean 14.1 × 8.7 μm) with an L/W ratio of 1.6–1.7 (mean 1.62). The Stieda body is flattened (~0.5 × 1.5 μm), the sub‐Stieda body is rounded (~1.5 × 2.5 μm), and the para‐Stieda body is absent. The sporocyst residuum, composed of clustered spherules, is ~3.5 × 3.5 μm. Sporozoites contain anterior and posterior refractile bodies and a nucleus. Molecular analysis of the 18S rRNA, 28S rRNA, and COI gene loci showed a 99.5% genetic similarity to Isospora neochmiae at the 18S rRNA locus and 99.2% and 97.7% similarities to Isospora manorinae at the 28S rRNA and COI loci, respectively. Phylogenetic analysis confirmed that the new species is closely related to I. manorinae. Based on these data, we propose this isolate as a new species, Isospora virescensae n. sp.

In the current study, Contracaecum jorgei Sardella, Mancini, Salinas, Simões & Luque, 2020 is reported from the common snook Centropomus undecimalis (Bloch, 1792) in the Rodrigo de Freitas lagoon in the State of Rio de Janeiro, southeastern Brazil. This anisakid species was recently described in wolffish in Argentina. Through comparative analyzes of genetic sequences deposited in GenBank with the sequencing of a locus of the cytochrome oxidase subunit 2 ( cox2 ) gene provided in the present study, the identification of C. jorgei was confirmed, at the same time that misidentified sequences of Contracaecum spp. were observed. These misidentified sequences were then discussed and reevaluated, expanding the reports of C. jorgei and, consequently, its geographic distribution in the Neotropical region. Finally, the current study highlights the importance of the findings and study of anisakid nematodes in commercial fish for the monitoring and prevention of human anisakiasis, which is openly neglected or confused with other gastrointestinal diseases worldwide.

Chivi vireos Vireo chivi (Vieillot, 1817) are passerine birds widely distributed throughout Brazil, but mainly observed in the Atlantic Forest of the South and Southeast regions of the country. In this context, the current study identifies a new species of Isospora Schneider, 1881 from V. chivi captured in the Marambaia Island, on the coast of the State of Rio de Janeiro, Southeastern Brazil. The oocysts of Isospora juruviarae Andrade & Berto n. sp. are subspheroidal to ovoidal, measuring on average 26 by 24 μm. Micropyle is absent or inconspicuous. Oocyst residuum absent, but polar granules are present. Sporocysts are ellipsoidal with pointed posterior end, measuring on average 17 by × 11 μm. Stieda and Sub-Stieda bodies are present. Sporocyst residuum is present among the vermiform sporozoites, which have refractile bodies and nucleus. This morphology was different from the other Isospora spp. recorded in the same family, superfamily and parvorder as the host. Molecular identification was targeted by the amplification and sequencing of two different loci of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene and one locus of the 18S small subunit ribosomal RNA (18S) gene. Phylogenetic analyses were not very efficient in forming monophyletic groups associated with host taxon, zoogeographical region or taxonomic character; however, they confirmed the identification as a new species through comparison with sequences from Isospora spp. of wild passerines. Finally, based on the morphological and molecular analyses of the oocysts recovered from the chivi vireo V. chivi in the current work, I. juruviarae is considered new to science, being the second species recorded in the host family Vireonidae and the first to have a supplementation by molecular identification.

A novel Eimeria Schneider, 1875 species is described from an Australian pied oystercatcher Haematopus longirostris Vieillot, in Western Australia. The pied oystercatcher was admitted to the Kanyana Wildlife Rehabilitation Centre (KWRC), Perth, Western Australia in a poor body condition, abrasion to its right hock and signs of partial delamination to its lower beak. Investigation into potential medical causes resulted in a faecal sample being collected and screened for gastrointestinal parasites. Unsporulated coccidian oocysts were initially observed in the faeces and identified as Eimeria upon sporulation. The sporulated oocysts (n = 20) are ellipsoidal, 20–21 × 12–13 μm in shape and have thick bi-layered walls which are c.2/3 of the total thickness. Micropyle is present, robust and protruding, and occasionally has a rounded polar body attached to the micropyle. Within the oocyst, a residuum, in addition, two to five polar granules are present. There are four ellipsoidal sporocysts 9–11 × 5–6 μm with flattened to half-moon shaped Stieda bodies. Sub-Stieda body and para-Stieda body are absent. The sporocysts contain sporocyst residuums composed of a few spherules scattered among the sporozoites. Within the sporozoites, anterior and posterior refractile bodies are present, but the nucleus is indiscernible. To further characterise the novel Eimeria species from H. longirostris, molecular analysis was conducted at the 18S ribosomal RNA locus, using PCR amplification and cloning. Two cloned sequences from the novel Eimeria were compared with those from other Eimeria spp. with the highest genetic similarity of 97.6

Spinetails are a suboscine passerines of the genus Synallaxis Vieillot, 1818 which have great interest for ornithology, given the wide diversity of 37 species that are distributed throughout the Neotropical region. Despite this wide diversity and distribution, Synallaxis spp. have never been recorded as hosts of coccidian parasites. In this context, the current study describes a new species of Isospora Schneider, 1881 from rufous-capped spinetails Synallaxis ruficapilla Vieillot, 1819 captured in the Itatiaia National Park, which is a federal conservation unit in Southeastern Brazil. The oocysts of Isospora pichororei Genovez-Oliveira & Berto n. sp. are subspheroidal to ovoidal, measuring on average 25 by 21 μm. Micropyle is present, but discrete. Oocyst residuum absent, but one or two polar granules are present. Sporocysts are ellipsoidal with slightly pointed posterior end, measuring on average 17 by 10 μm. Stieda and sub-Stieda bodies are present. Sporocyst residuum is clustered among the vermiform sporozoites, which have striations, refractile bodies and nucleus. This morphology was different from the other Isospora spp. recorded in the host family Furnariidae. Molecular identification was targeted by the amplification and sequencing of a locus of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. This sequence had the highest similarity of 99.5% with a sequence deposited for Isospora oliveirai Ortúzar-Ferreira & Berto, 2020, which is a coccidian species that parasitizes suboscine tityrids Schiffornis virescens (Lafresnaye, 1838), also in the Itatiaia National Park. Phylogenetic analysis grouped some species in subclades, including I. pichororei with I. oliveirai; however, it was inconclusive in an expectation of parasite-host coevolution. Finally, I. pichororei is established as new to science, being the first description from Synallaxinae and the third description from Furnariidae. Furthermore, this is the first Isospora sp. from the host family Furnariidae to have a molecular supplementation by sequencing a locus of the cox1 gene of the mitochondrial genome.

Reduncin bovids of Kobus spp. (Bovidae: Reduncini) are natively distributed in sub-Saharan Africa, although some populations have been introduced into parks and zoos around the world. The majority of the species has declining populations, being categorized as threatened by the International Union for Conservation of Nature and Natural Resources; therefore, protective measures for the conservation of Kobus spp. are necessary, including the study of their parasites, such as the eimeriid coccidians (Apicomplexa: Eimeriidae). In this context, the aim of the current study was to brings together the taxonomic data from the descriptions and reports of Eimeria spp. from reduncin bovids, based on the detailed morphological identification of Eimeria congolensis Ricci-Bitti, Pampiglione & Kabala, 1973 from a new host subspecies, the common waterbuck Kobus ellipsiprymnus ellipsiprymnus (Ogilbyi, 1833), in a safari park of Portugal. Five Eimeria spp. are recorded from reduncin bovids, in addition to six more reports identified generically as Eimeria sp., which were compared and taxonomically rearranged. The oocysts identified as E. congolensis in the current study were compatible with the original description and were supplemented for some taxonomic characters not originally included, such as: Stieda body flattened to nipplelike, sub-Stieda body rounded to trapezoidal, sporocyst residuum granular and membrane-bound, in addition to greater details of the micropyle, among others. Finally, the current study highlights the importance of studying the coccidians of reduncin bovids for the conservation of Kobus spp. due to the possibility of these Eimeria spp. are extra-intestinal parasites, which can potentially cause severe coccidiosis associated with increased morbidity and mortality in certain threatened populations of Kobus spp.

The current work aimed to analyze, morphologically, statistically, and molecularly, oocysts shed from plumbeous pigeons, Patagioenas plumbea (Vieillot, 1818), from a locality at 2197 m of altitude near the Agulhas Negras peak, the highest point of the State of Rio de Janeiro, southeastern Brazil. The oocysts were extremely polymorphic, being subspheroidal, ovoidal, or ellipsoidal, in addition to having the random presence/absence of characteristic features associated with the oocyst wall, such as micropyle, micropyle cap, lateral micropyle, and outer veil/rough wall. Linear regression confirmed the extreme polymorphism of oocysts, showing that if all combinations of taxonomic characters in oocysts (morphotypes) were overestimated, 19 different species could be identified/described. In contrast, the means comparison analysis between oocysts with the presence/absence of characteristic features and the histograms showed equivalences and regularity in the distribution in the classes of measures, which indicate the presence of a single species in the measured oocysts. Molecular analyses were performed from the isolation of individual oocysts of different morphotypes, which had their genetic material extracted, amplified, and sequenced in 4 non-overlapping loci in the cox1 and cox3 genes and fragments of the small and large subunit rDNA of mitochondrial DNA. The sequences were 100% identical between the morphotypes, with the exception of a very small divergence observed at the locus that partially covers the cox3 gene. The phylogenetic analysis was inconclusive for the locus within the cox1 gene traditionally used for eimeriid coccidians; however, the other loci should have a promising future for phylogenetic studies when more sequences for the same genic regions are deposited in GenBank. Finally, the multifactorial analysis of the current work supported that the polymorphic oocysts shed from P. plumbea are a single species, which was named Eimeria patagioenasae , making this the twenty-second eimerian description from Columbiformes.

ABSTRACT: The green-winged saltator Saltator similis (d’Orbigny & Lafresnaye, 1837) is a passerine bird highly valued by bird breeders and a target of illegal wildlife trafficking. Coccidian chromists are etiological agents of coccidiosis, which may be asymptomatic and enzootic in bird populations when environmental conditions are favorable. However, epizootic outbreaks with severe disease can occur due to environmental changes. In this context, this study reports a case of coccidiosis in a free-living juvenile specimen of S. similis captured at the Itatiaia National Park in southeastern Brazil. Typical clinical signs of coccidiosis were observed, and it was associated with greenish mucoid diarrhea containing a high density of coccidian oocysts. Three Isospora spp. were specifically identified in 14 fecal samples (fecal droplets) collected over two hours. Isospora saltatori (Berto, Balthazar, Flausino & Lopes, 2008) had the highest density and positivity throughout most of the collection period. Finally, this paper discusses the importance of the continuous evaluation of the health of birds as bioindicators and their coccidian ecological biomarkers as one of the strategies for evaluating the conservation status of Itatiaia National Park.

Genovez-Oliveira J.L., Andrade L.A.S., Oliveira M.S., Lima V.M., Berto B.P. & Oliveira a.A. 2023. Fungi isolated from wild birds in the Marambaia Island, Rio de Janeiro State, southeastern Brazil. Pesquisa Veterinaria Brasileira 44:e07383, 2024. Departamento de Biologia Animal, Instituto de Ciencias Biologicas e da Saude, Universidade Federal Rural do Rio de Janeiro, BR -465 Km 7, Seropedica, RJ 23897-000, Brazil. E-mail: bertobp@ufrrj.br In Brazil, the Atlantic Forest has been suffering from deforestation, which has had impacts on its flora, fauna, and microbiota. However, the fungal diversity present in these environments is little known and studied. In this study, a total of 90 samples of 45 wild birds (45 feathers and 45 feces) were collected in Ilha da Marambaia, southeastern Brazil. Filamentous fungi isolated from these samples were identified through macroscopic and microscopic characteristics. Some isolates were identified by molecular biology using the PCR technique. Acremonium, Alternaria, Aspergillus, Cunninghamella, Curvularia, Eurotium, Fusarium, Geotrichum, Neosartorya, Pestalotia, Paecilomyces, Penicillium, Rhizopus, Mucor and Syncephalastrum were identified. These results indicate the presence of saprophytic fungi species in the feathers and feces of wild birds of the capture site. Further studies should be conducted to elucidate if the mycobiota profile modifies with anthropization and if it interferes with bird health and environmental recovery.

This article reports on a golden-billed saltator Saltator aurantiirostris Vieillot, 1817, kept in captivity outside its natural distribution area, in the proximities of the Itatiaia National Park, as a new host for Isospora similisi Coelho, Berto, Neves, Oliveira, Flausino & Lopes, 2013. Additionally, a supplementary molecular identification is provided through the sequencing of three non-overlapping loci of mitochondrial DNA and one locus of the 18S small subunit ribosomal RNA (18S) gene. All the taxonomic features of the I. similisi oocysts shed by S. aurantiirostris were equivalent to those originally described from Saltator similis d'Orbigny & Lafresnaye, 1837. The new sequenced loci were identical, or showed 99.9% similarity, to the samples of I. similisi from S. similis and S. aurantiirostris, confirming the same species from both hosts. Lastly, I. similisi is estimated as a junior synonym of Isospora formarum McQuistion & Capparella, 1992, due to the morphological similarities and wide distribution of its hosts in the Neotropical region. Therefore, this study encourages future taxonomic inquiries into I. similisi collected from other Saltator spp. in order to establish this synonymization of I. formarum with I. similisi, and hence, its wide distribution and dispersion in the Neotropical region, including across the Andes mountains.

This study aimed to verify the diversity of ticks in wild birds of remnant fragments of the Atlantic Forest biome in the municipality of Piraí, Rio de Janeiro state, and to detect pathogenic agents in the ticks collected. Birds were captured between June 2016 and April 2017. The collected ticks were identified using a specific dichotomous key. Tick DNA was tested using polymerase chain reaction (PCR) for Borrelia spp., Rickettsia spp., Ehrlichia spp., Anaplasma spp., and Babesia spp. In total, 150 birds were captured, including 64 species, 18 families, and 5 orders. Of these, 22 (14.67%) of 18 different species were parasitized by Amblyomma spp. (n=7), Amblyomma longirostre (n=10), Amblyomma sculptum (n=1), and Amblyomma parkeri (n=21). Only one Amblyomma sp. amplified specific DNA fragments for Rickettsia amblyommatis, whereas the others were negative for Borrelia spp., Ehrlichia spp., Anaplasma spp., and Babesia spp. The avifauna play an important role in maintaining the life cycle of ticks, in addition to contributing to the dispersion of arthropods and the microorganisms transmitted by them.

A novel Eimeria sp. from a captive-bred bilby (Macrotis lagotis Reid, 1837) has been identified in Western Australia. The bilby was bred at the Kanyana Wildlife Rehabilitation Centre, Perth, as part of the National Bilby Recovery Plan. Oocysts (n = 31) irregular blunt ellipsoidal, 17-18 x 11-12 (17.2 x 11.3); length/width (L/W) ratio 1.4-1.5 (1.5). Wall bi-layered, 0.8-1.0 (0.9) thick, outer layer smooth, c.2/3 of total thickness. Micropyle barely discernible. Oocyst residuum is absent, but 2-3 small polar granules are present. Sporocysts (n = 31) ovoidal, 7-8 x 5-6 (7.8 x 5.7); L/W ratio 1.3-1.4 (1.4). Stieda, sub-Stieda and para-Stieda bodies absent or indiscernible; sporocyst residuum present, usually as an irregular body consisting of numerous granules that appear to be membrane-bound or sometimes diffuse among sporozoites. Sporozoites vermiform with a robust refractile body. Further molecular characterization was conducted on the sporulated oocysts. At the 18S locus, it sat in a large clade of the phylogenetic tree with two isolates of Eimeria angustus from quendas (Isoodon obesulus Shaw, 1797) and the Choleoeimeria spp. It shared the highest identity with E. angustus (KU248093) at 98.84%; at the COI gene locus, it was unique and most closely related to Choleoeimeria taggarti, which is hosted by another species of marsupial, the yellow-footed antechinus (Antechinus flavipes flavipes), with 90.58% genetic similarity. Based on morphological and molecular data, this isolate is a new species and named as Choleoeimeria yangi n. sp.

Guinea fowls, Numida meleagris (L., 1758), are galliform birds native to sub-Saharan Africa, but introduced in several countries around the world for domestic breeding and/or animal production. This species is considered more resistant to disease by Eimeria spp. than other domestic galliform birds. Here we review the Eimeria spp. known to infect species of Numididae and provide the first molecular identification of an Eimeria sp. from Guinea fowls. There are currently 3 named eimerians from Guinea fowls; Eimeria numidae Pellerdy, 1962; Eimeria grenieri Yvoré and Aycardi, 1967; and Eimeria gorakhpuri Bhatia & Pande, 1967. We reviewed each of these species descriptions and documented their taxonomic shortcomings. From that, we suggest that E. gorakhpuri is a junior synonym of E. numidae. In conclusion, we have morphologically redescribed in detail E. grenieri from N. meleagris from Rio de Janeiro and provided molecular supplementation through sequencing of three non-overlapping loci in cox1 and cox3 genes and fragments of small and large subunit mitochondrial rDNA.

ObjectiveTo analyze the presence of protozoan parasites in bird coprolites from the Tremembé Formation (Oligocene of the Taubaté Basin).MaterialsTwenty avian coprolites embedded in pyrobituminous shale matrices.MethodsSamples were rehydrated and subjected to spontaneous sedimentation.ResultsPaleoparasitological analyses revealed oocysts compatible with the Eimeriidae family (Apicomplexa) and one single Archamoebae (Amoebozoa) cyst.ConclusionsThe present work increases the amount of information about the spread of infections throughout the Cenozoic Era and reveals that the Brazilian paleoavifauna played an important role in the Apicomplexa and Amoebozoa life cycles.SignificanceThis is the first record of protozoans in avian coprolites from the Oligocene of Brazil. These findings can help in the interpretation of phylogenies of coccidian parasites of modern birds, as certain taxonomic characters observed in the Oligocene Protozoa characterize monophyletic groups in current molecular phylogenetic analyses.LimitationsNone of the oocysts were sporulated; therefore, it is not possible to identify the morphotypes to genus or species.Suggestions for further researchOur results create new perspectives related to biogeographic studies of the parasitic groups described and may improve the understanding of the temporal amplitude of parasitic evolutionary relationships between Protozoans and birds.