Perot Museum of Nature and Science

Cloning from historically cryopreserved cells offers a potential means to restore lost genetic variation or increase the representation of particular lineages within bottlenecked species, provided such biobanked materials are archived for such genetic rescue applications. One species for which cloning can provide genetic management benefits is Przewalski’s horse, Equus przewalskii. All ~1800 living Przewalski’s horses, distributed across ex situ breeding facilities and in situ reintroduction sites, are descended from one or more of the five founder lineages established by the 12 horses captured from the wild between 1898 and 1947. Since the 1970s, the San Diego Zoo Wildlife Alliance Biodiversity Bank’s Frozen Zoo® (Escondido, CA, USA) has biobanked cells or tissues of 575 individuals spanning many generations. A pedigree analysis of a subset of deceased individuals represented in the San Diego Zoo Wildlife Alliance Biodiversity Bank’s Frozen Zoo® revealed an underrepresented male that lived from 1975 to 1998, Studbook Number 615 (also known as Kuporovitch), who would be of high value for breeding if cloned. Here, we report that two healthy clones were produced from this cell line using cross-species somatic cell nuclear transfer from 2020 to 2023. Their identification as clones was verified by a standard horse-pedigree genotyping panel, and, for one clone, a whole genome sequencing comparison to the original donor was performed. This is the first time that multiple healthy clones surviving the perinatal period have been produced for an endangered species.

Bird–window collisions (BWCs) are a major threat to avian populations, annually causing up to one billion bird deaths in the US alone and untold numbers of fatalities worldwide. Until recently, there has been limited institutional and governmental recognition of this issue and few coordinated, national‐level efforts to address it. To fill this need, citizen‐science campaigns have stepped in to generate scientific information about BWCs, raise public awareness, and advocate for policy and actions to reduce collisions. We review the BWC issue and showcase how citizen‐science programs in multiple countries have achieved these outcomes. Additional citizen‐driven successes in addressing BWCs are possible if key constraints are overcome, including funding limitations and challenges of proactively engaging stakeholders who can reduce BWCs at scale. Addressing this global conservation issue will also require building upon the recent increase in attention to BWCs by government agencies, nongovernmental organizations, commercial entities, and professional scientists.

A multiparous pygmy hippopotamus (Choeropsis liberiensis) dam produced three consecutive calves that died acutely at 13-15 wk of age from bacterial sepsis, for which diagnostic and therapeutic intervention was not possible. Streptococcus iniae (Cases 1 and 3), Escherichia coli (Case 2), and an unidentified member of the family Pasteurellaceae (Case 1) were identified in postmortem tissues through bacterial culture followed by standard and molecular identification methods. After the loss of two calves, a series of vaccinations were administered to the dam during the third pregnancy to enhance transplacental and colostral transfer of antibodies to the calf. The third calf did not survive, and the source of the bacterial infection in these three calves was undetermined. Prior to and after the birth of the fourth calf, nutritional and nutraceutical supplements were provided to the dam and calf. Additionally, pest control around the barn was enhanced. The fourth calf survived. Pygmy hippopotamus calves at the age of 13-15 wk may have increased susceptibility to bacterial infection, possibly due to waning maternally derived immunity. The findings in these cases, combined with a previous association of S. iniae in pygmy hippopotamus deaths, suggest that this bacterium is an especially important pathogen of the endangered pygmy hippopotamus.

The largest dinosaurs were enormous animals whose body mass placed massive gravitational loads on their skeleton. Previous studies investigated dinosaurian bone strength and biomechanics, but the relationships between dinosaurian trabecular bone architecture and mechanical behavior has not been studied. In this study, trabecular bone samples from the distal femur and proximal tibia of dinosaurs ranging in body mass from 23–8,000 kg were investigated. The trabecular architecture was quantified from micro-computed tomography scans and allometric scaling relationships were used to determine how the trabecular bone architectural indices changed with body mass. Trabecular bone mechanical behavior was investigated by finite element modeling. It was found that dinosaurian trabecular bone volume fraction is positively correlated with body mass similar to what is observed for extant mammalian species, while trabecular spacing, number, and connectivity density in dinosaurs is negatively correlated with body mass, exhibiting opposite behavior from extant mammals. Furthermore, it was found that trabecular bone apparent modulus is positively correlated with body mass in dinosaurian species, while no correlation was observed for mammalian species. Additionally, trabecular bone tensile and compressive principal strains were not correlated with body mass in mammalian or dinosaurian species. Trabecular bone apparent modulus was positively correlated with trabecular spacing in mammals and positively correlated with connectivity density in dinosaurs, but these differential architectural effects on trabecular bone apparent modulus limit average trabecular bone tissue strains to below 3,000 microstrain for estimated high levels of physiological loading in both mammals and dinosaurs.

Have you ever wondered about your extended family? Paleoanthropologists—scientists who study the history of the human family—discovered bones in South Africa belonging to a species of human relative they call Homo naledi. The bones were located deep underground in the Rising Star Cave, in a chamber that is difficult to access. Scientists gave the nickname Neo to one of the most complete skeletons they found. The bones of Neo and other Homo naledi individuals are helping us understand more about the family history of our own species, Homo sapiens. This article describes how Neo was found and what we have learned about him and his species, Homo naledi. It will also tell you what research scientists do to solve mysteries like how old Neo was when he died and how his bones got into the cave.

A nearly complete skeleton of a new hadrosaurid, Kamuysaurus japonicus gen. et sp. nov., was discovered from the outer shelf deposits of the Upper Cretaceous Hakobuchi Formation of the Yezo Group in Hobetsu area of Mukawa town in Hokkaido, Japan. Kamuysaurus belongs to the sub-clade of Hadrosaurinae, Edmontosaurini, and forms a monophyly with Laiyangosaurus and Kerberosaurus from the northern Far East. Kamuysaurus has a long anterior platform for the nasofrontal sutural surface, which may indicate the presence of a small supracranial crest, similar to a sub-adult form of Brachylophosaurus based on the extension of the nasofrontal sutural surface. The Dispersal Extinction Cladogenesis analysis with the 50% Majority Rule consensus tree suggests that the clade of Kamuysaurus, Laiyangosaurus, and Kerberosaurus may have dispersed into Asia prior to the late Campanian and the potential endemism of this clade during the late Campanian and early Maastrichtian in the northern Far East. The results of both Dispersal Extinction Cladogenesis and Ancestral State Reconstruction analyses imply that the marine-influenced environment in North America during the Campanian may have played an important role for the hadrosaurid diversification in its early evolutionary history.

Four heteropod lizard trackways discovered in the Hasandong Formation (Aptian-early Albian), South Korea assigned to Sauripes hadongensis, n. ichnogen., n. ichnosp., which represents the oldest lizard tracks in the world. Most tracks are pes tracks (N = 25) that are very small, average 22.29 mm long and 12.46 mm wide. The pes tracks show “typical” lizard morphology as having curved digit imprints that progressively increase in length from digits I to IV, a smaller digit V that is separated from the other digits by a large interdigital angle. The manus track is 19.18 mm long and 19.23 mm wide, and shows a different morphology from the pes. The predominant pes tracks, the long stride length of pes, narrow trackway width, digitigrade manus and pes prints, and anteriorly oriented long axis of the fourth pedal digit indicate that these trackways were made by lizards running bipedally, suggesting that bipedality was possible early in lizard evolution.

Abstract This study is a quantitative evaluation of historic nesting levels of the Kemp's ridley sea turtle (Lepidochelys kempii) in 1947 based on (1) the Herrera film of a 1947 arribada, (2) Hildebrand's 1947 report regarding the 1947 arribada shown in the Herrera film, (3) historic documentation regarding the Herrera film, and (4) current nesting characteristics related to arribada size relative to total nests for a season. Using this information in a quantitative approach, we estimate a total of approximately 26 916 nests during the 1947 arribada recorded by Herrera. Based on current nesting trends, we also predict that this would equate to approximately 121 517 total nests for the 1947 season (range of 82 514–209 953), which would represent approximately 48 607 nesting females (range of 33 006–83 981). This suggests that during and prior to the 1947 nesting season a relatively robust population of Kemp's ridleys existed, which could support arribadas consisting of at least 26 916 females. The results of the current study indicate that from 1947 through 1985 (the lowest point in the decline of Kemp's ridley nesting) the Kemp's ridley population underwent a 99.4% decline (range of 99.2–99.7%) from an estimated 121 517 nests per season in 1947 to 702 nests per season in 1985. Although the Kemp's ridley population has been recovering since the 1985 season, it has deviated from its exponential recovery rate and has declined in recent years. The current levels of nesting (12 053 nests in 2014) are still relatively low at 9.9% (range of 5.7–14.6%) of the total estimated nests that occurred in 1947. It is currently not clear whether this population will recover to historic levels considering recent nesting trends and due to a variety of threats that may hinder its recovery.