Evidence of Chronic Tusk Trauma and Compensatory Scoliosis in Mammuthus meridionalis from Madonna della Strada (Scoppito, L’Aquila, Italy)

Abstract

A remarkably well-preserved skeleton of a male Mammuthus meridionalis, approximately 60 years old, from the Early Pleistocene that is housed at the Castle of L’Aquila (Italy) exhibits a fractured left tusk with severe bone erosion of the alveolus and premaxillary bone, as well as marked spinal deformities. The cranial region underwent ultrasonographic, radiological, and histological examinations, while morphological and biomechanical analyses were conducted on the vertebral column. Microscopic analysis revealed intra vitam lesions, including woven bone fibers indicative of early bone remodeling and lamellar bone with expanded and remodeled Haversian systems. These findings are consistent with osteomyelitis and bone sequestration, likely resulting from chronic pulpitis following the tusk fracture, possibly due to an accident or interspecific combat. The vertebral column shows cervical scoliosis, compensatory curves, fusion between the first cervical vertebrae, and asymmetric articular facets, suggesting postural adaptations. Evidence of altered molar wear and masticatory function also support long-term survival post-trauma. Additionally, lesions compatible with spondyloarthropathy, an inflammatory spinal condition not previously documented in Mammuthus meridionalis, were identified. These findings provide new insights into the pathology and adaptive responses of extinct proboscideans, demonstrating the critical role of (paleo)histological methods in reconstructing trauma, disease, and aspects of life history in fossil vertebrates.

1. Introduction

Mammuthus meridionalis [1] is one of the best-known extinct proboscidean species native to Eurasia during the Early Pleistocene [2]. First described from the Upper Valdarno Basin in Tuscany, this species is well represented in the Italian fossil record [3,4,5,6,7,8,9].

Relevant information about large Quaternary mammals can be obtained from paleopathological investigations. The identification of skeletal abnormalities and degenerative joint disease, as well as evidence of bone lesions caused by trauma, can provide insights into the adaptation patterns and social behavior of these prehistoric animals.

Palaeoloxodon, Mammuthus, and Mammut bone pathology is an understudied topic, often only mentioned and not specifically described in the literature; bone diseases, however, have been reported in proboscideans [10,11,12,13,14,15,16,17], An extensive review of cases is reported in Haynes and Klimowicz [11], and Barbosa et al. [18] described several bone pathologies in Notiomastodon platensis. Most of the reported lesions are traumatic fractures, often associated with natural accidents, fighting between males, falls on icy terrain, or vertebral erosions [19], predominantly in the woolly mammoth [20]. No articles specifically address Mammuthus meridionalis.

Osteoarthritis and degenerative diseases have been detected in vertebral bones and joints, likely related to aging, obesity, or loading stress on unstable terrain. Rothschild and Laub [21] described multiple cases of arthritis in the foot bones of Mammut americanum.

Osteoporosis and metabolic diseases, identified especially in ribs, can suggest nutritional deficiencies or hormonal alterations. In Poland, Krzemińska et al. [13] found signs of bone density loss consistent with Kashin–Beck disease, a metabolic disorder.

Some fossils show osteolytic lesions or swellings compatible with chronic infections. Rothschild et al. [22] documented typical signs of chronic recurrent multifocal osteomyelitis in large mammals.

Bone neoplasms and tumors, though rare, have been documented, including benign tumors such as osteochondromas. Garcês et al. [23] discussed the identification of tumors through imaging prehistoric specimens, including mammoths.

Some mammoths show pathological vertebral protrusions (e.g., osteophytes), congenital malformations, or fused thoracic vertebrae, which are indicative of chronic mechanical stress. Wojtal et al. [24] studied more than 3000 vertebrae in Eastern Europe with such abnormalities.

At archaeological sites such as Kyle (Canada), multiple fractures and bone chips have been found, suggesting human slaughter or hunting [25].

One of the most significant paleontological discoveries in Italy is a nearly complete skeleton of Mammuthus meridionalis, which is housed in the Aragonese Castle of L’Aquila. It represents the best-preserved example of this species recovered from Italian territory and exhibits distinctive anatomical features that have attracted the attention of both paleontologists and veterinarians. The skeleton was discovered in March 1954 in a sandy layer of an early Pleistocene lacustrine–fluvial succession cropping out in the Santarelli clay quarry at Madonna della Strada (Scoppito), in the L’Aquila Basin (Figure 1).

Palynological data from lignite-rich clay deposits overlying the sandy layer where the fossil was discovered indicate an age of approximately 1.3 million years [26]. The specimen is a male estimated to have been 57–60 years old at the time of death. It was a remarkably large individual, standing at about 4 m at the withers and measuring 6.5 m from the tip of the tusk to the end of the tail. The specimen, however, is missing its left tusk, which has never been found in the areas surrounding the discovery site [27].

The latest restoration and diagnostic work, completed in 2015 and extensively reported in Rossi et al. [28], clarified the shape of the skull, which had previously been reconstructed with an overly high cranial vault and an anomalous nuchal fossa and revealed extensive portions of bone that were previously not visible and pathological features that prompted a dedicated paleopathological investigation.

The studies focused on the evaluation and interpretation of the observed lesions: an extensive irregularly shaped cavity on the left premaxilla; a fractured left tusk socket; various vertebrae, particularly the first and second cervical vertebrae (atlas and axis), that were previously described by A.M. Maccagno [27]; and evident deviations in the conformation and alignment of the spine.

Following gross inspection, ultrasonic investigation, and radiographic analysis, a microscopic examination of the premaxillary bone tissue was performed in order to characterize the in vivo lesions, allowing for disease diagnosis and to improve our understanding of degradation processes potentially due to diagenetic changes [29]. The individual vertebrae in the spine were subjected to a morphological study, followed by a biomechanical assessment.

2. Materials and Methods

2.1. Paleopathological Evidence on the Skull

The skull, which was detached from the rest of the skeleton during restoration, was examined macroscopically, with particular attention to the large bony defect present in the left premaxillary sinus and the fracture of the ipsilateral tusk. Observations of the premaxillary lesion aimed to characterize the morphology of its margins and fundus, both of which are crucial for confirming or excluding a direct traumatic origin and for evaluating any potential relationship with the animal’s death. The anatomical extent of the lesion was also examined to determine whether it could be linked to the partial absence of the left tusk (Figure 2).

2.2. Ultrasound Investigation Conducted on the Left Premaxilla

Ultrasound has been successfully applied in archaeology for non-invasive internal diagnostics [30], and its use in estimating bone properties such as density and strength is well established in medical research (e.g., [31], among others). Given the limited availability of CT scanning, we explored the potential of ultrasound as a preliminary, non-invasive method for internal assessment in a paleontological context.

To investigate the internal structure of the left alveolus of the Mammuthus meridionalis premaxilla, ultrasound analyses were performed to verify the presence of the alveolar portion of the tusk or any other material added during the restoration work carried out in the 1950s.

The propagation speed of the ultrasonic pulse in a medium depends on its density and elastic properties. For this reason, a PROCEQ TICO device (PROCEQ S A, Schwerzenbach, Switzerland), operating at a frequency of 54 kHz, was used to acquire data on the structural characteristics of the specimen. The instrument was calibrated through the analysis of three reference samples:

• Right tusk (ivory), used to obtain the characteristic signal of ivory.
• Stump of the left tusk (ivory + mastic), to detect the signal behavior in the presence of composite materials.
• Reconstructed right premaxilla (mastic + iron), to determine if metal is present.

The measurements were performed by applying the two probes directly to the external surface of the premaxilla at the level of the left alveolus, and ultrasonic responses were recorded at multiple points. The measurements, including calibration tests, were conducted at seven distinct points (M1–M7); the distance traveled by the ultrasonic wave (d, in cm), the transit time (t, in microseconds), and the wave velocity (V, in m/s) were recorded.

2.3. Radiographic Analysis

To rule out the possibility that the morphology and extent of the premaxillary lesion might not be related to pathology but rather to postmortem damage or to an accident that occurred at the construction site prior to its discovery/recovery, we performed a radiographic examination of the edges of the lesion and, as much as possible, of part of the fundus to confirm our assessments.

Conventional radiography was the only viable option given the skull’s size and weight (approximately 500 kg), which made a spiral CT scan, though far more comprehensive and effective, logistically unfeasible.

The examinations were conducted using a low-frequency, digitized Agfa portable radiographic system with 20 × 30 cm cassettes in latero-lateral projection. The digitized images were acquired directly on site.

Prior to the X-ray analysis, small chips of material were collected from the same areas where the radiographs were performed. Both the chips and the corresponding radiographs were labeled with the abbreviation “C” followed by a number (Figure 3).

2.4. Polarizing Microscope Analysis

The chips were processed through thin-sectioning and examined under a polarizing microscope to determine their bony nature, internal structure, and histological arrangement. The microscope used was a Leitz Ortholux II Pol-BK (Leitz, Wetzlar, Germany) petrographic model, equipped with 10× eyepieces and 3.5, 6.3, 16, and 40× magnification objectives. A Nikon Coolpix 955 digital camera was mounted for image acquisition. Observations were conducted under polarized light using both plane-polarized light (PPL) and crossed nicols (XPL).

The thin sections were embedded in araldite resin, sectioned with a microtome, and polished to a standard thickness of 30 microns. For additional optical analysis, gypsum (λ = 550 nm) and calcite (λ/4) compensators were employed (for observation purposes only).

2.5. Molar Functional Morphology

The teeth corresponding to the third and last molars (M3) show an advanced degree of wear indicative of an old individual.

The upper molars are heavily worn but still allowed for the identification of seven plates on the right and eight on the left, with a possible ninth suggested by a faint residual enamel trace.

Only the posterior half of the right lower molar is preserved, with four complete plates and the posterior portion of a fifth; the anterior segment has been reconstructed and is therefore unsuitable for functional analysis. For this reason, the functional assessment focused on the left lower molar, which is significantly better preserved than the upper molars. It bears nine clearly identifiable and presumably functional plates; a tenth, although still distinguishable in the lateral view, is extensively worn and likely no longer functional.

Both right molars, upper and lower, were found detached from their alveoli [27], a condition that likely contributed to their poorer state of preservation compared to the left molars (Figure 4).

2.6. Morphological Asymmetries of the Skeleton

Macroscopic examination of the remaining axial skeleton revealed marked morphological asymmetries, particularly in several spinous processes and in the pelvic arch. In contrast, the appendicular skeleton did not exhibit significant pathological alterations. Given these findings, the morphological analysis was focused exclusively on the axial skeleton, even in cases where individual vertebrae did not display overt intra vitam morphological changes. Prior to the morphological analysis, specific criteria were defined to exclude vertebrae deemed unsuitable for quantitative assessment. Exclusion was based on the following conditions: significant anatomical portions of the vertebra were missing; structural reconstructions involved the vertebral arch or spinous process had been carried out; or the photographic documentation was insufficient for reliable morphometric analysis. These criteria were applied through a combined approach, integrating direct macroscopic inspection with historical records provided by Maccagno [27].

Maccagno’s records indicate that several spinous processes were already partially fractured postmortem at the time of excavation. The affected vertebrae include cervical vertebrae C5 and C6; thoracic vertebrae T6 through T11; and the last lumbar vertebra.

We conducted the morphological study using photographic material acquired by the project management during the latest restoration work. The images, taken from the caudal surface of individual vertebrae aligned on the coronal plane, were obtained during the stage of reassembly. These photographs were subsequently processed using Adobe Photoshop CC 2015, applying a custom method developed from previous work in both paleontological and clinical-radiographic contexts [32,33,34,35,36,37].

The images were analyzed at the highest possible resolution to clearly define the anatomical landmarks required for the measurements. We have also assigned a number to each landmark (see landmarks table) and connected them to each other (see axes table) in order to trace 4 horizontal axes and 1 vertical axis. The axis of the anterior articular processes was not used in the study due to insufficient data.

Therefore, the analysis was based on the measurement of three angles formed between the vertebral longitudinal axis and its transverse components, deviations from which would indicate abnormal curvature or rotational asymmetry (Figure S1).

Three angular measurements were calculated to assess the morphometric deviations of the spinous processes relative to the main vertebral axes:

• Angle 1: between the spinous process axis (from the apex to neural arch or spinous base) and the perpendicular to the vertebral body’s maximum transverse diameter (Figure S2a);
• Angle 2: between the spinous process axis and the perpendicular to the line connecting the transverse processes (Figure S2b);
• Angle 3: between the spinous process axis and the perpendicular to the line connecting the anterior articular processes (Figure S2c).

Angular values were plotted in cranio-caudal sequence on a reference grid relative to azimuthal zero. Positive and negative deviations were visualized as a broken line, allowing for the identification of asymmetry patterns, including across vertebral regions with partial data. To the right of it, we have positive values, and to the left, negative values, just as we did conventionally when calculating angles (Figure S2d,e,f). This method was used to detect vertebral asymmetries that are potentially indicative of a scoliotic condition, in which the longitudinal and transverse axes of the vertebrae variably deviate from the neutral (zero-degree) alignment [38,39].

Even though photographic material was used, a careful macroscopic examination of the articular surfaces of the first two cervical vertebrae was performed. Taphonomic alterations were ruled out as a cause of bone alterations, according to the recommendations of Ortner [40] and Barbosa et al. [41].

3. Results

3.1. Paleopathological Evidence on the Skull

The cranial lesion (Figure 2) presents an evidently irregular morphology measuring approximately 15 × 12 × 20 cm. The latero-ventral margins appear completely blunt, with signs of lithic pitting in the most distal portion. In contrast, the mid-dorsal edges exhibit less rounding. The smooth internal surface and blunt borders are indicative of a chronic, lithic process, likely of septic origin. The elongated shape of the lesion, which extends cranio-ventrally, suggests bone erosion associated with purulent exudate, which developed along gravity-driven pathways, consistent with fistolization [40,42]. Traces of lithic activity further extend distally in the same direction.

Frontal observation of the skull revealed clear asymmetry in the tusk alveoli. The left alveolus appears narrower and more compressed latero-medially. The associated left tusk is fractured (Figure 2), with partial remnants of the crown showing an irregular outer margin. The central portion of the alveolar cavity lacks ivory, while a long oblique fracture line, involving both the medullary canal and the root (which is still firmly anchored to the socket), suggests antemortem trauma.

3.2. Ultrasound Investigation Conducted on the Left Premaxilla

This morphological evidence was complemented by ultrasonic analysis, which provided preliminary quantitative data on the internal structure and restoration materials. The interpretation of the results was made possible by comparing the measurements taken for the left premaxilla with three reference samples: the right tusk (ivory), the left tusk stump (ivory and mastic), and the right reconstructed premaxilla (mastic and iron). These served as internal standards for differentiating between fossil ivory, restoration fillers, and metallic components.

The values recorded for the left tusk, when compared with the reference samples, confirmed the presence of an oblique fracture. This area was treated with an adhesive material consistent with the type of mastic commonly used during restoration works in the 1950s. The measurements taken for the premaxilla, on the other hand, indicate values consistent with the presence of a pulp cavity within the alveolus, as the transmission speed closely matched that of bone tissue. The ultrasound investigation results are summarized in

Table 1. Ultrasound investigation results.

Measurement	d (cm)	t (µs)	V (m/s)	Material	Observations
M1	22.5	267	843	Ivory	Right tusk
M2	24	282	851	Ivory	Right tusk
M3	14.5	248	585	Ivory + Mastic	Left stump
M4	20	450	444	Ivory + Mastic	Left stump
M5	13	248	524	Bone	Left premaxilla
M6	14	254	551	Bone	Left premaxilla
M7	20	218	917	Mastic + Iron	Right premaxilla

.

3.3. Radiographic Findings

The radiographic examination revealed that, at all sampling points along the margins of the cranial defect, there is a peripheral band of radiolucency that gradually attenuates toward the interior. This pattern suggests progressive bone rarefaction surrounding the lesion. In addition, a periosteal reaction is evident near the margins in images corresponding to sampling points C1 and C2.

At point C1 (Figure 5a), the radiograph highlights the absence of clear radiodensity, with well-defined areas of marginal osteolysis. At point C3 (Figure 5b), pronounced vascularization is also visible, manifesting as longitudinal radiolucent striations, consistent with reactive hyperemia or chronic inflammatory remodeling.

3.4. Histopathological Results

From the various sampling points, the lesion appears to exhibit both osteolytic and osteo-productive characteristics simultaneously (Figure 6, Figure 7 and Figure S3).

At point C1, a layer of woven bone transitioning into lamellar bone was observed above normal compact lamellar bone.

At point C2, compact adult lamellar bone was evident, as indicated by remodeling signs and the presence of remnants from ancient Haversian systems.

The most significant findings were observed at point C3, which shows a typical picture of woven bone in the early reparative phase, along with lamellar spongy bone containing dilated Haversian canals. These features may be associated with inflammation, resembling an early stage of non-specific hematogenous osteomyelitis in which the inflammatory process rapidly spreads through surrounding bone tissue, producing confluent microinjuries, enlarged resorption cavities, and interconnecting canals [40].

3.5. Molar Functional Morphology

In the upper molars, the wear is extremely advanced, particularly on the anterior palatal surfaces. Despite a better overall state of preservation, the left molar shows greater wear, with much of the occlusal surface flattened and the plate contours no longer distinguishable.

The left lower molar exhibits marked asymmetrical wear, especially on the antero-buccal side, and displays a distinct concavity in the occlusal surface in both the transverse and longitudinal planes (Figure 4).

Based on the degree of molar wear and the large body size of the individual, the specimen is estimated to have been at least 57–60 years old [43]. In fossil elephants, age determination is typically carried out by comparing the progressive wear stages of mandibular molars with those observed in extant African and Asian elephants [44,45], which are generally smaller in body size and may have shorter lifespans. As noted by Palombo [43], the prolonged somatic growth typical of male elephants (slowing around the age of 20–25 but continuing well into older age) likely enabled the specimen to reach one of the largest body sizes ever recorded for its species, as confirmed by a body mass estimate of 11.43 tons by Romano et al. [46]. Given the prolonged growth of male elephants and comparisons with other large-bodied fossil proboscideans [47,48], it is plausible that individuals of M. meridionalis might have reached 65–70 years of age.

3.6. Morphological Asymmetries of the Skeleton

The cervical vertebrae are rigidly articulated, primarily through the transverse processes, forming a structure well-suited to supporting a raised head. Consequently, their relative mobility was likely limited, even without the evident arthritic degeneration affecting the first three vertebrae. As Maccagno [27] observed, “the articulation surfaces appear rough, tubercular, and often molded over one another, such that the atlas and axis appeared tightly interlocked at the time of recovery, with the superior neural arch of the atlas recessed and fused to that of the axis”. These vertebrae were later separated and examined individually.

The atlas is well preserved except for the reconstructed right transverse process. Its articular surface, along with that of the axis, is heavily deformed, marked by tuberosities and ankylosis, likely eliminating the normal rotational movement around the dens. Though currently separated, both vertebrae retain clear signs of dorsal ossification and osteoarthritic changes (Figure 8). Notably, pronounced asymmetry of the facet joints is evident in both vertebrae: the left articular surfaces are markedly smaller than the right, consistent with a pre-existing cervical or cervicothoracic scoliosis, as further indicated by their partial fusion (Figure 9a).

The articular facets of the posterior surface of the atlas and the articular facet for the axis appear as a rugose bony spur due to proliferated bone. The medullary canal is narrowed and altered due to bone overgrowth. On the right articular facet, two V-shaped fractures are observed (Figure 9a).

The left margin of the caudal vertebral endplate of the axis shows small, rounded, crater-like, smooth-walled, subchondral erosions (Figure 9b).

Macroscopic examination of the preserved skeleton revealed pronounced morphological asymmetries, particularly in several spinous processes and in the pelvic arch. In contrast, no significant alterations were noted in the appendicular skeleton.

The morphological analysis began with a vertebra-by-vertebra macroscopic assessment, enabling accurate specimen selection. Our observations were cross-referenced with those recorded by Maccagno [27] in her original report. Notably, Figure 1 in Tables I and IV of that report illustrate the vertebral column in a lateral view, showing the bases of the spinous processes as firmly joined. This provided a solid foundation for proceeding with our investigation.

As Maccagno noted, “Most of the vertebrae were almost completely preserved, though very fragile: each was consolidated with mastic and internal reinforcement and completed of any missing parts”. In light of this, and to ensure a rigorous analysis, we performed a visual inspection of each vertebra, as detailed in the previous section.

This examination confirmed that the cervical vertebrae had undergone minimal human modification, limited primarily to areas of substantial loss. Following this evaluation, we compiled the results of the morphological study, including measurements of the three angles (

Table 2. Summary of morphological features of the vertebral column.

VERTEBRAE	ANGLE 1	ANGLE 2	ANGLE 3
C1	−16.5°	/	/
C2	−1.7°	/	/
C3	−2°	/	/
C7	−1.7°	1.5°	/
T1	10.1°	8.5°	11.8°
T2	6.2°	7°	9.3°
T4	13.5°	/	9.3°
T5	9.8°	/	9.5°
T7	3.7°	/	5.8°
T8	7.4°	/	11.9°
T10	8.6°	−0.8°	1.6°
T16	−0.2°	/	−0.1°
T17	−8.2°	/	−7.1°
T18	−4.8°	−2.4°	/
T19	−2.4°	−5.4°	−4.3°
L1	−8.3°	/	1.9°
L2	4.7°	/	/
L3	3.6°	/	/

).

Downstream of the first scoliotic curve, which progressively develops, additional curves can be observed. These are referred to as “compensatory” curves, as they function to redistribute biomechanical loads in a way that is adaptive but changes the morphology [49].

Certain spinal segments (C4 to C6, T3 to T6, and T11 to T15) were excluded from the analysis because they did not meet the established inclusion criteria. Nevertheless, C7 shows a tendency to return toward the midline, followed by a rightward axial deviation at T1, which reaches its maximum at T4. From this point, the angle gradually decreases, approaching a new neutral axis at T16. At T17, a new deviation begins and persists until L1).

The data clearly demonstrate deviations in the vertebral axes, consistent with the presence of scoliosis. The major cervicothoracic curve is followed by a smaller compensatory curve. Particularly notable is the marked deviation of the spinous processes, which orient toward the ipsilateral transverse and articular processes, a characteristic feature of scoliotic vertebrae [50] (Figure 10).

As detailed in the results section, angles 2 and 3, which relate to deviations in the transverse and articular processes and the major axis of the vertebral body, closely follow the deviation of the spinous process, although to varying extents. On careful observation, we can see that angle 1 of C7, T10, and L1 fall in the opposite azimuth with respect to the other angles. This phenomenon can be explained by the inclination of the transverse axes which, with respect to the axis of the soma, can differ from each other.

However, due to the limited number of measurable cases, no further statistical correlation was attempted between these angular measurements.

Regarding the pelvis, a pronounced asymmetry is evident between the right and left ischial bones, with the left being considerably more prominent. The pubic symphysis is incomplete and displaced, with the apices directed leftward and the caudal extension of the left ischium visibly exceeding that of the right. The obturator foramina, from the ventral view, are clearly asymmetric (Figure 11).

The long-term survival of the animal after the loss of its left tusk is supported by the chronic postural adaptations of the spine, as well as by the altered wear patterns observed in the molars, indicating compensatory masticatory behavior over an extended period.

4. Discussion

The hypothesis that the absence of the right tusk is not due to taphonomic processes was first proposed by Maccagno [27] during a detailed monographic study of the specimen. The missing tusk could not be found and antemortem loss was tentatively suggested. Based on the new observations presented in this study, that hypothesis can now be confirmed. The oblique fracture observed on the right alveolus is entirely consistent with breakage patterns documented in extant elephants, particularly in adult males following intraspecific combat. Moreover, the presence of a pathological bone response, including extensive remodeling and reactive bone deposition, provides further evidence of a traumatic event occurring during life and of the individual’s prolonged survival after the loss of its tusk. These features allow us to rule out a taphonomic origin and support the conclusion that the tusk was lost antemortem.

The results suggest that the specimen is a case of “monolateral tusklessness”, meaning it had lost one tusk. In proboscideans bearing tusks, such a condition may result from congenital agenesis, as observed in some elephants [51,52], or be secondary to trauma, such as tusk fracture followed by rare alveolar avulsion. African elephants (Loxodonta africana) rely on their tusks for digging, carrying objects, and combat [11]. Remarkably, they exhibit a high capacity for healing following traumatic injury and appear to experience minimal pain from dentinal or pulpal damage [53].

In our specimen, the left tusk displays a clear oblique fracture, exposing the medullary canal. This type of lesion is typically caused by torsional forces exerted along the long axis of the tusk, which is commonly observed in adult males after intraspecific combat. Given the presumed ethological similarities between mammoths and modern elephants, it is reasonable to infer that the fracture occurred during adulthood and subsequently led to the formation of a fistulous tract toward the maxillary sinus.

Indeed, the involvement of the pulp cavity in ascending infections following tusk fractures is well documented in elephants [54,55,56]. In both extant elephants and other tusked mammals, trauma represents the most frequent dental pathology. Fractures exposing the pulp canal often result in the development of chronic fistulas with purulent discharge [57]. These infections become persistent due to limited drainage through the pulp canal, compounded by reactive tissue proliferation, leading to exudate stagnation and involvement of the dental apex.

The pulp responds to injury with a robust reparative reaction, significantly supported by the extensive vascular supply through the wide base of the tusk. Given the known osteolytic potential of the purulent exudate, it is reasonable, based on analogy with other species, to hypothesize that a fistulous tract within the diploë of the premaxillary sinus developed in our mammoth specimen. This interpretation is corroborated by the presence of two distinct osteolytic erosions, which appear to have been excavated by fluid under gravitational influence.

The observed pattern of extensive, localized skeletal destruction prompts a differential diagnosis that includes both infectious processes (e.g., tuberculosis) and neoplastic conditions [58]. However, the macroscopic and histological features do not support a diagnosis of malignancy. Instead, they are consistent with a non-specific infectious etiology. Similar infectious processes involving abscess formation with sclerotic margins and minimal or non-existent periosteal reaction have been documented in other South American Late Pleistocene mammals [17].

In malignant neoplasms, osteolytic lesions may be accompanied by a minimal osteoblastic response. Yet, the presence of newly formed trabecular bone and marrow space infilling, features that were observed here, are more typical of reactive or reparative changes [59].

Benign tumors, which are generally slow growing, exhibit sharply demarcated osteolytic margins with a narrow transition zone between healthy and affected bone. This boundary is often accentuated by a sclerotic rim resulting from host bone reaction. Conversely, aggressive neoplasms show a broader, poorly defined transition zone.

As for periosteal reactions, a solid, continuous thickening of the periosteum is indicative of a slow-growing process. In contrast, the formation of thin, lamellar periosteal bone suggests a more rapidly evolving lesion, though not necessarily malignant; such features are also commonly observed in osteomyelitis [60].

The most reliable diagnostic indicators of osteomyelitis in skeletal remains are the presence of a drainage canal (cloaca) and the formation of sequestra in association with periosteal new bone (involucrum) [61].

Tuberculosis (TB), caused by Mycobacterium tuberculosis or M. bovis, is a significant disease in elephants, with documented outbreaks in both captive and wild populations. It is an ancient affliction [62], first recorded in elephants over two millennia ago in Sri Lanka [63]. Direct paleopathological evidence of TB in Late Pleistocene Mammut americanum foot bones has been reported [21].

In humans, TB can affect the bony walls of the nasal cavity via secondary extension from the mucosa, though such involvement is rare. In our specimen, no additional bone involvement was identified, as would typically be expected in TB cases. Furthermore, the morphology of tuberculous lesions in dry bone is nonspecific and often overlaps with other infectious pathologies. Nonetheless, certain general characteristics can aid differential diagnosis, particularly when considering lesion distribution patterns relative to age [64,65].

Tuberculosis characteristically follows two pathological phases: an exudative phase, in which the infection permeates marrow spaces and causes devitalization of cancellous bone with the formation of central sequestra (caries), and a granulomatous proliferative phase, leading to localized cavitation and bone destruction. Notably, these processes elicit minimal, if any, reactive bone formation, and the surrounding bone often presents signs of perifocal or generalized osteoporosis.

In the skull, tuberculous lesions are typically small (≤2 cm), round, and lytic, occasionally featuring a central “moth-eaten” sequestrum. Their lamellar borders and fine fissures may give the bone a slightly porous appearance. In contrast to purulent osteomyelitis, extensive cortical sequestra are rare in TB, and periosteal reaction is usually absent [61].

Porosity at the margin of a lytic lesion is more indicative of malignant neoplasms, yet no such widespread porosity or other lytic foci were detected in our case. The absence of additional lesions across the skeleton supports the exclusion of metastatic disease.

Lastly, the microscopic evaluation did not reveal deep focal damage, such as round voids or linear tunnels due to post-burial microbial invasion from soil organisms [66]. Apart from minor superficial endolithic activity, no taphonomic alterations confounding the diagnosis were identified.

With regard to the macroscopic assessment of the spine, it is important to consider Maccagno’s original observations of M. meridionalis. In her 1962 report, she described the cervical vertebrae, particularly the atlas and axis, as “tenaciously welded” at the time of discovery, with C3 showing extensive and impressive arthritic alterations. Although these three vertebrae are now separated, due to a preparatory intervention carried out in 1954, clear signs of osteoarthritic changes remain evident. The rest of the spinal column presents marked deviations of the spinous processes, particularly in the thoracic region.

The rugous bony spur areas in the atlas resemble the features described in a congenital fusion of two sesamoids by Barbosa et al. [67]; this does not indicate a spondyloarthropathy but an enthesitis. Our alteration has the characteristics of spondyloarthritis and among the types of arthritis, spondyloarthropathy is the most common in the fossil record [68].

The smooth, rounded, and crater-shaped subchondral erosions observed in the axis are diagnostic of joint manifestations of spondyloarthropathy (SpA) [69]. They are, in fact, similar to those reported by Barbosa et al. [70] in a fragment of the pelvis of a Catonyx cuvieri and Barbosa et al. [10] in a caudal vertebra of Nothrotherium maquinense, which was clearly recognized by the presence of smooth resorption surrounding the alteration [41,71].

Barbosa et al. [70] report numerous similar cases of SpA in several prehistoric species from the Pleistocene.

Spondyloarthropathies (SpAs) refer to multifactorial diseases affecting the axial and peripheral skeleton. The exact mechanism behind most SpAs remains unclear, but genetics and environmental factors are involved in the pathogenesis of the disease [72]. SpA includes a wide variety of joint diseases, including those in which the proliferation of new bone (osteoarthritis), peripheral joint fusion, and a tendency for spine and sacroiliac fusion (as in our case) are the main features and those in which the key characteristic is bone erosion [73,74,75]. Differentiating between the different types of spondyloarthropathy is not always possible; furthermore, osteonecrosis resulting from defective blood flow due to trauma, especially if repeated and chronic, low-grade, or involving microtrauma, must also be considered [10].

Spondyloarthropathy has been observed in 5–8% of extant Elephas maximus and Loxodonta africana, and is similarly represented in extinct Mammuthus primigenius, but not in Mammut [73,74,76] and has never been reported in Mammuthus meridionalis.

The vertebral alterations observed in our Mammuthus are very similar to those reported in [15] in a Chilean gomphothere, an extinct group of proboscideans related to modern elephants. They described asymmetries in a cervical and a thoracic vertebra (with the spinous process deviating to the left), degenerative joint disease in thoracic and lumbar vertebrae, and fusion in thoracic vertebrae, findings consistent with spondyloarthropathy.

The atlas fractures on its right endplate could likely be due to mechanical separation from the axis, but it is also possible to classify this vertebral injury as Type A (vertebral body compression) injuries caused by axial compression with or without flexion and affecting the vertebral body almost exclusively, or subtype A2.1 (coronal split fracture) according to the system of classification proposed by Magerl et al. [77]. The left articular facet is more worn and the spinal canal is modified by bone proliferation. These suggest that the injury was caused by axial compression forces on the vertebral body without a loss of vertebral stability [77]. Infectious processes can also generate joint erosions, typically in a marginal location, with subchondral erosions being a late development [40,68].

There are various reports in the literature on deformities of the vertebral body, subchondral erosion, and vertebral fusions in primitive species [78,79,80,81]. Barbosa et al. [70] macroscopically examined 2075 bones assigned to six species of large Pleistocene sloths from the Brazilian Intertropical Region and reported an atlas of an adult individual of Catonyx cuvieri, which was found associated with the skull and axis, with a calcified sheet on both occipital condyle articular surfaces. They also observed several alterations including changes to the axis and third cervical vertebra in a Catonyx cuvieri from Toca do Garrincho, which has fused due to the formation of new bone; a calcified plate on the articular surfaces that articulates with both the occipital condyles of the atlas and axis in Eremotherium laurillardi; osteophytes in the thoracic and lumbar vertebrae of Ocnotherium giganteum; and osteophytes on the axis in Glossotherium.

The asymmetries in size and orientation of the vertebral articular facets occur in a condition called tropism that appears to be a common condition in proboscideans, in both modern and fossil animals, and have been observed in numerous different individuals (e.g., [11,13,82,83,84]) and are remarkably well displayed in Anolaima gomphothere vertebrae [16]. It has been suggested that asymmetry in thoracic and lumbar vertebrae could be the result of the strengthening of the mid-back [19], a response to biomechanical stresses, or due to developmental or mass changes during the lifetime of an individual [15]. In our case, the asymmetrical orientation of the vertebral facets and the different depths cannot be considered a normal condition as they are accompanied by bone augmentation, osteoarthritic alterations, and other pathological aspects.

For the morphological study, we first performed a vertebra-by-vertebra macroscopic evaluation, cross-referencing our observations with those documented by Maccagno [27]. Her report indicates that the spinous processes of some vertebrae were partially fractured post-mortem. These specific vertebrae are listed in the Materials and Methods section.

Photographic analysis of the vertebral column, using caudal views of the vertebrae aligned in the coronal plane, allowed for the evaluation of axial asymmetries with biomechanical implications. This investigation confirmed a significant deformation of the first two cervical vertebrae, along with evidence of ossification between them in the dorsal region. Additionally, a pronounced asymmetry of the articular facets was observed: on both vertebrae, the joint surfaces on the left side are markedly reduced compared to the right (Figure 9), supporting the presence of cervical or cervicothoracic scoliosis.

Further analysis of the vertebral axes revealed additional scoliotic curves, which are best interpreted as compensatory (Figure 10). These develop to functionally redistribute mechanical loads, though they reflect a clearly altered morphology. The initial curvature, beginning at the level of the first cervical vertebrae, shows a deviation to the left. This likely resulted from asymmetric muscular traction and compression on the side opposite to the load shift, influenced by the unilateral presence of a tusk.

The evident vertebral asymmetries are consistent with scoliotic lesions that were previously described in other species [50,85,86].

A unique case of fusion involving several bones in Mammuthus trogontherii chosaricus from the southeastern West Siberian Plain was described by Shpansky et al. [87]. The fusion affected the distal ends of the tibia and fibula, as well as the calcaneus and astragalus. It was likely the result of trauma, probably a dislocation with displacement of the calcaneus and astragalus, accompanied by soft tissue damage. The injury led to a deep ankylosis, which in turn caused significant morphological alterations in the diaphysis and distal end of the tibia.

Based on these objective findings, and irrespective of the exact nature of the trauma, it is evident that the animal experienced a long-term asymmetrical loading of the skull. This mechanical imbalance may explain the pronounced vertebral remodeling and the fusion between the atlas and axis observed in our specimen.

The reciprocal influences between static and dynamic loads acting on the skull and the axial skeleton are well recognized in the literature. In quadrupedal mammals, the transmission of forces differs markedly from that in humans due to differences in posture. In these animals, the vertebral column is primarily subjected to horizontal loads generated by muscular activity rather than vertical gravitational forces [88]. In this context, the gravitational vector in quadrupeds acts more along the horizontal plane relative to the vertebral bodies, resulting in a predisposition toward kyphotic or lordotic curvature adaptations rather than the scoliotic tendencies more commonly observed in bipedal humans [89,90,91].

The lack of equality of the upper and left lower molars wears pattern suggests unbalanced masticatory forces, likely related to the loss of the left tusk. The resulting asymmetry may have contributed to the cranio-cervical adaptations observed in the vertebral column, supporting the hypothesis of a biomechanical response to chronic functional imbalance.

The estimated age places the individual at the upper end of the known lifespan range for both extinct and extant elephants. However, considering the pathological condition affecting the specimen, it is likely that death occurred before reaching its full potential lifespan.

The evidence of altered molar wear patterns further supports the hypothesis of long-term survival following tusk loss, indicating chronic changes in masticatory function. There are no current estimates exist on the long-term mortality risk associated with cranial bone fractures or osteolytic lesions in prehistoric proboscideans, such as Mammuthus, and the sequelae of cranial trauma remain a significant topic in paleopathological research. While we cannot determine with certainty the full sequence of events in this individual’s life, the integration of pathological skeletal features with age-at-death estimates for the Madonna della Strada mammoth suggests a life marked by survival from early trauma and subsequent chronic conditions.

The morphological study has the limitation of measuring morphometric angles based on photographic samples, although rigorous and precise sample inclusion criteria were adopted. A more precise investigation could be achieved by processing images obtained through computerized tomography.

5. Conclusions

The nearly complete, well-preserved, and carefully restored skeleton of the mammoth from Madonna della Strada represents an exceptional opportunity to investigate bone lesions and their underlying pathogenesis in this individual. This specimen is among the most significant fossil mammal discoveries from the Early Pleistocene. Its importance lies in its completeness and preservation: it is one of the most intact and best-preserved adult Mammuthus meridionalis specimens ever found in Italy or elsewhere in northwestern Europe. The excellent condition of the remains has permitted a detailed anatomical and pathological investigation, and has also provided insights into the progression of its pathological conditions over time. Spondyloarthropathy may be the likely diagnosis for some of the atlas/axis vertebral lesions and is reported here for the first time in Mammuthus meridionalis.

In summary, a defensive tusk fracture likely exposed the dental pulp, leading to septic infection. This infection, having spread through the pulp cavity, would have caused chronic septic osteomyelitis with sequestration of bone in the premaxillary region. Radiographic imaging of the lesion margins, together with histological analysis under plane and polarized light, confirms the dual osteolytic and osteoproductive nature of the lesion.

The absence of one tusk likely resulted in asymmetrical mechanical loading on the skull, particularly increasing stress on the left side of the atlanto-axial (atlanto-epistropheal) joint. This hyperload may have induced spondiloartropatic lesions and progressive arthrodesis, ultimately involving the entire joint. Compensatory muscular activity, particularly from the cervical and scapular girdle muscles on the left side, likely acted to stabilize the head position, resulting in the scoliotic spinal deformations observed.

This study underscores the value of meticulous anatomical restoration that is faithful to the species’ morphology, combined with paleohistological approaches and biomechanical analysis, to accurately diagnose and interpret bone lesions in paleontological specimens.